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[PATCH v28 09/11] Add support for min/max aggregates for IVM
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* [PATCH v28 09/11] Add support for min/max aggregates for IVM
@ 2023-05-31 11:58 Yugo Nagata <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: Yugo Nagata @ 2023-05-31 11:58 UTC (permalink / raw)

Supporting min and max is more complicated than count, sum, or avg.

For an example of min, when tuples are inserted, the current min value
in the view and the min value in the inseteted tuples are compared,
then the smaller one is used as the latest min value. On the other
hand, when tuples are deleted, if the current min value in the view
equals to the min in the deleted tuples, we need re-computation the
latest min value from base tables. Otherwise, the current value in
the view remains.
---
 src/backend/commands/createas.c |  45 +++
 src/backend/commands/matview.c  | 644 +++++++++++++++++++++++++++++++-
 2 files changed, 680 insertions(+), 9 deletions(-)

diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index c8aa558f2e..c40ea6b2bc 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -1312,6 +1312,51 @@ check_aggregate_supports_ivm(Oid aggfnoid)
 		case F_AVG_FLOAT8:
 		case F_AVG_INTERVAL:
 
+		/* min */
+		case F_MIN_ANYARRAY:
+		case F_MIN_INT8:
+		case F_MIN_INT4:
+		case F_MIN_INT2:
+		case F_MIN_OID:
+		case F_MIN_FLOAT4:
+		case F_MIN_FLOAT8:
+		case F_MIN_DATE:
+		case F_MIN_TIME:
+		case F_MIN_TIMETZ:
+		case F_MIN_MONEY:
+		case F_MIN_TIMESTAMP:
+		case F_MIN_TIMESTAMPTZ:
+		case F_MIN_INTERVAL:
+		case F_MIN_TEXT:
+		case F_MIN_NUMERIC:
+		case F_MIN_BPCHAR:
+		case F_MIN_TID:
+		case F_MIN_ANYENUM:
+		case F_MIN_INET:
+		case F_MIN_PG_LSN:
+
+		/* max */
+		case F_MAX_ANYARRAY:
+		case F_MAX_INT8:
+		case F_MAX_INT4:
+		case F_MAX_INT2:
+		case F_MAX_OID:
+		case F_MAX_FLOAT4:
+		case F_MAX_FLOAT8:
+		case F_MAX_DATE:
+		case F_MAX_TIME:
+		case F_MAX_TIMETZ:
+		case F_MAX_MONEY:
+		case F_MAX_TIMESTAMP:
+		case F_MAX_TIMESTAMPTZ:
+		case F_MAX_INTERVAL:
+		case F_MAX_TEXT:
+		case F_MAX_NUMERIC:
+		case F_MAX_BPCHAR:
+		case F_MAX_TID:
+		case F_MAX_ANYENUM:
+		case F_MAX_INET:
+		case F_MAX_PG_LSN:
 			return true;
 
 		default:
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index aa6bf2694a..fa65e4aeb0 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -73,6 +73,34 @@ typedef struct
 
 #define MV_INIT_QUERYHASHSIZE	16
 
+/* MV query type codes */
+#define MV_PLAN_RECALC			1
+#define MV_PLAN_SET_VALUE		2
+
+/*
+ * MI_QueryKey
+ *
+ * The key identifying a prepared SPI plan in our query hashtable
+ */
+typedef struct MV_QueryKey
+{
+	Oid			matview_id;	/* OID of materialized view */
+	int32		query_type;	/* query type ID, see MV_PLAN_XXX above */
+} MV_QueryKey;
+
+/*
+ * MV_QueryHashEntry
+ *
+ * Hash entry for cached plans used to maintain materialized views.
+ */
+typedef struct MV_QueryHashEntry
+{
+	MV_QueryKey key;
+	SPIPlanPtr	plan;
+	OverrideSearchPath *search_path;        /* search_path used for parsing
+											 * and planning */
+} MV_QueryHashEntry;
+
 /*
  * MV_TriggerHashEntry
  *
@@ -109,6 +137,7 @@ typedef struct MV_TriggerTable
 	TupleTableSlot *slot;		/* for checking visibility in the pre-state table */
 } MV_TriggerTable;
 
+static HTAB *mv_query_cache = NULL;
 static HTAB *mv_trigger_info = NULL;
 
 static bool in_delta_calculation = false;
@@ -169,6 +198,9 @@ static void append_set_clause_for_sum(const char *resname, StringInfo buf_old,
 static void append_set_clause_for_avg(const char *resname, StringInfo buf_old,
 						  StringInfo buf_new, StringInfo aggs_list,
 						  const char *aggtype);
+static void append_set_clause_for_minmax(const char *resname, StringInfo buf_old,
+							 StringInfo buf_new, StringInfo aggs_list,
+							 bool is_min);
 static char *get_operation_string(IvmOp op, const char *col, const char *arg1, const char *arg2,
 					 const char* count_col, const char *castType);
 static char *get_null_condition_string(IvmOp op, const char *arg1, const char *arg2,
@@ -177,17 +209,30 @@ static void apply_old_delta(const char *matviewname, const char *deltaname_old,
 				List *keys);
 static void apply_old_delta_with_count(const char *matviewname, const char *deltaname_old,
 				List *keys, StringInfo aggs_list, StringInfo aggs_set,
-				const char *count_colname);
+				List *minmax_list, List *is_min_list,
+				const char *count_colname,
+				SPITupleTable **tuptable_recalc, uint64 *num_recalc);
 static void apply_new_delta(const char *matviewname, const char *deltaname_new,
 				StringInfo target_list);
 static void apply_new_delta_with_count(const char *matviewname, const char* deltaname_new,
 				List *keys, StringInfo target_list, StringInfo aggs_set,
 				const char* count_colname);
 static char *get_matching_condition_string(List *keys);
+static char *get_returning_string(List *minmax_list, List *is_min_list, List *keys);
+static char *get_minmax_recalc_condition_string(List *minmax_list, List *is_min_list);
+static char *get_select_for_recalc_string(List *keys);
+static void recalc_and_set_values(SPITupleTable *tuptable_recalc, int64 num_tuples,
+					  List *namelist, List *keys, Relation matviewRel);
+static SPIPlanPtr get_plan_for_recalc(Oid matviewOid, List *namelist, List *keys, Oid *keyTypes);
+static SPIPlanPtr get_plan_for_set_values(Oid matviewOid, char *matviewname, List *namelist,
+						Oid *valTypes);
 static void generate_equal(StringInfo querybuf, Oid opttype,
 			   const char *leftop, const char *rightop);
 
 static void mv_InitHashTables(void);
+static SPIPlanPtr mv_FetchPreparedPlan(MV_QueryKey *key);
+static void mv_HashPreparedPlan(MV_QueryKey *key, SPIPlanPtr plan);
+static void mv_BuildQueryKey(MV_QueryKey *key, Oid matview_id, int32 query_type);
 static void clean_up_IVM_hash_entry(MV_TriggerHashEntry *entry, bool is_abort);
 
 /*
@@ -2102,6 +2147,8 @@ apply_delta(Oid matviewOid, Tuplestorestate *old_tuplestores, Tuplestorestate *n
 	ListCell	*lc;
 	int			i;
 	List	   *keys = NIL;
+	List	   *minmax_list = NIL;
+	List	   *is_min_list = NIL;
 
 
 	/*
@@ -2183,6 +2230,17 @@ apply_delta(Oid matviewOid, Tuplestorestate *old_tuplestores, Tuplestorestate *n
 				append_set_clause_for_avg(resname, aggs_set_old, aggs_set_new, aggs_list_buf,
 										  format_type_be(aggref->aggtype));
 
+			/* min/max */
+			else if (!strcmp(aggname, "min") || !strcmp(aggname, "max"))
+			{
+				bool	is_min = (!strcmp(aggname, "min"));
+
+				append_set_clause_for_minmax(resname, aggs_set_old, aggs_set_new, aggs_list_buf, is_min);
+
+				/* make a resname list of min and max aggregates */
+				minmax_list = lappend(minmax_list, resname);
+				is_min_list = lappend_int(is_min_list, is_min);
+			}
 			else
 				elog(ERROR, "unsupported aggregate function: %s", aggname);
 		}
@@ -2212,6 +2270,8 @@ apply_delta(Oid matviewOid, Tuplestorestate *old_tuplestores, Tuplestorestate *n
 	if (old_tuplestores && tuplestore_tuple_count(old_tuplestores) > 0)
 	{
 		EphemeralNamedRelation enr = palloc(sizeof(EphemeralNamedRelationData));
+		SPITupleTable  *tuptable_recalc = NULL;
+		uint64			num_recalc;
 		int				rc;
 
 		/* convert tuplestores to ENR, and register for SPI */
@@ -2230,10 +2290,18 @@ apply_delta(Oid matviewOid, Tuplestorestate *old_tuplestores, Tuplestorestate *n
 			/* apply old delta and get rows to be recalculated */
 			apply_old_delta_with_count(matviewname, OLD_DELTA_ENRNAME,
 									   keys, aggs_list_buf, aggs_set_old,
-									   count_colname);
+									   minmax_list, is_min_list,
+									   count_colname, &tuptable_recalc, &num_recalc);
 		else
 			apply_old_delta(matviewname, OLD_DELTA_ENRNAME, keys);
 
+		/*
+		 * If we have min or max, we might have to recalculate aggregate values from base tables
+		 * on some tuples. TIDs and keys such tuples are returned as a result of the above query.
+		 */
+		if (minmax_list && tuptable_recalc)
+			recalc_and_set_values(tuptable_recalc, num_recalc, minmax_list, keys, matviewRel);
+
 	}
 	/* For tuple insertion */
 	if (new_tuplestores && tuplestore_tuple_count(new_tuplestores) > 0)
@@ -2425,6 +2493,70 @@ append_set_clause_for_avg(const char *resname, StringInfo buf_old,
 	);
 }
 
+/*
+ * append_set_clause_for_minmax
+ *
+ * Append SET clause string for min or max aggregation to given buffers.
+ * Also, append resnames required for calculating the aggregate value.
+ * is_min is true if this is min, false if not.
+ */
+static void
+append_set_clause_for_minmax(const char *resname, StringInfo buf_old,
+							 StringInfo buf_new, StringInfo aggs_list,
+							 bool is_min)
+{
+	char *count_col = IVM_colname("count", resname);
+
+	/* For tuple deletion */
+	if (buf_old)
+	{
+		/*
+		 * If the new value doesn't became NULL then use the value remaining
+		 * in the view although this will be recomputated afterwords.
+		 */
+		appendStringInfo(buf_old,
+			", %s = CASE WHEN %s THEN NULL ELSE %s END",
+			quote_qualified_identifier(NULL, resname),
+			get_null_condition_string(IVM_SUB, "mv", "t", count_col),
+			quote_qualified_identifier("mv", resname)
+		);
+		/* count = mv.count - t.count */
+		appendStringInfo(buf_old,
+			", %s = %s",
+			quote_qualified_identifier(NULL, count_col),
+			get_operation_string(IVM_SUB, count_col, "mv", "t", NULL, NULL)
+		);
+	}
+	/* For tuple insertion */
+	if (buf_new)
+	{
+		/*
+		 * min = LEAST(mv.min, diff.min)
+		 * max = GREATEST(mv.max, diff.max)
+		 */
+		appendStringInfo(buf_new,
+			", %s = CASE WHEN %s THEN NULL ELSE %s(%s,%s) END",
+			quote_qualified_identifier(NULL, resname),
+			get_null_condition_string(IVM_ADD, "mv", "diff", count_col),
+
+			is_min ? "LEAST" : "GREATEST",
+			quote_qualified_identifier("mv", resname),
+			quote_qualified_identifier("diff", resname)
+		);
+		/* count = mv.count + diff.count */
+		appendStringInfo(buf_new,
+			", %s = %s",
+			quote_qualified_identifier(NULL, count_col),
+			get_operation_string(IVM_ADD, count_col, "mv", "diff", NULL, NULL)
+		);
+	}
+
+	appendStringInfo(aggs_list, ", %s, %s",
+		quote_qualified_identifier("diff", resname),
+		quote_qualified_identifier("diff", IVM_colname("count", resname))
+	);
+}
+
 /*
  * get_operation_string
  *
@@ -2527,19 +2659,44 @@ get_null_condition_string(IvmOp op, const char *arg1, const char *arg2,
  * list to identify a tuple in the view. If the view has aggregates, this
  * requires strings representing resnames of aggregates and SET clause for
  * updating aggregate values.
+ *
+ * If the view has min or max aggregate, this requires a list of resnames of
+ * min/max aggregates and a list of boolean which represents which entries in
+ * minmax_list is min. These are necessary to check if we need to recalculate
+ * min or max aggregate values. In this case, this query returns TID and keys
+ * of tuples which need to be recalculated.  This result and the number of rows
+ * are stored in tuptables and num_recalc repectedly.
+ *
  */
 static void
 apply_old_delta_with_count(const char *matviewname, const char *deltaname_old,
 				List *keys, StringInfo aggs_list, StringInfo aggs_set,
-				const char *count_colname)
+				List *minmax_list, List *is_min_list,
+				const char *count_colname,
+				SPITupleTable **tuptable_recalc, uint64 *num_recalc)
 {
 	StringInfoData	querybuf;
 	char   *match_cond;
+	char   *updt_returning = "";
+	char   *select_for_recalc = "SELECT";
 	bool	agg_without_groupby = (list_length(keys) == 0);
 
+	Assert(tuptable_recalc != NULL);
+	Assert(num_recalc != NULL);
+
 	/* build WHERE condition for searching tuples to be deleted */
 	match_cond = get_matching_condition_string(keys);
 
+	/*
+	 * We need a special RETURNING clause and SELECT statement for min/max to
+	 * check which tuple needs re-calculation from base tables.
+	 */
+	if (minmax_list)
+	{
+		updt_returning = get_returning_string(minmax_list, is_min_list, keys);
+		select_for_recalc = get_select_for_recalc_string(keys);
+	}
+
 	/* Search for matching tuples from the view and update or delete if found. */
 	initStringInfo(&querybuf);
 	appendStringInfo(&querybuf,
@@ -2554,10 +2711,11 @@ apply_old_delta_with_count(const char *matviewname, const char *deltaname_old,
 						"UPDATE %s AS mv SET %s = mv.%s OPERATOR(pg_catalog.-) t.%s "
 											"%s"	/* SET clauses for aggregates */
 						"FROM t WHERE mv.ctid OPERATOR(pg_catalog.=) t.ctid AND NOT for_dlt "
-					")"
-					/* delete a tuple if this is to be deleted */
-					"DELETE FROM %s AS mv USING t "
-					"WHERE mv.ctid OPERATOR(pg_catalog.=) t.ctid AND for_dlt",
+						"%s"						/* RETURNING clause for recalc infomation */
+					"), dlt AS ("			/* delete a tuple if this is to be deleted */
+						"DELETE FROM %s AS mv USING t "
+						"WHERE mv.ctid OPERATOR(pg_catalog.=) t.ctid AND for_dlt"
+					") %s",							/* SELECT returning which tuples need to be recalculated */
 					count_colname,
 					count_colname, count_colname, (agg_without_groupby ? "false" : "true"),
 					(aggs_list != NULL ? aggs_list->data : ""),
@@ -2565,10 +2723,25 @@ apply_old_delta_with_count(const char *matviewname, const char *deltaname_old,
 					match_cond,
 					matviewname, count_colname, count_colname, count_colname,
 					(aggs_set != NULL ? aggs_set->data : ""),
-					matviewname);
+					updt_returning,
+					matviewname,
+					select_for_recalc);
 
-	if (SPI_exec(querybuf.data, 0) != SPI_OK_DELETE)
+	if (SPI_exec(querybuf.data, 0) != SPI_OK_SELECT)
 		elog(ERROR, "SPI_exec failed: %s", querybuf.data);
+
+
+	/* Return tuples to be recalculated. */
+	if (minmax_list)
+	{
+		*tuptable_recalc = SPI_tuptable;
+		*num_recalc = SPI_processed;
+	}
+	else
+	{
+		*tuptable_recalc = NULL;
+		*num_recalc = 0;
+	}
 }
 
 /*
@@ -2751,6 +2924,349 @@ get_matching_condition_string(List *keys)
 	return match_cond.data;
 }
 
+/*
+ * get_returning_string
+ *
+ * Build a string for RETURNING clause of UPDATE used in apply_old_delta_with_count.
+ * This clause returns ctid and a boolean value that indicates if we need to
+ * recalculate min or max value, for each updated row.
+ */
+static char *
+get_returning_string(List *minmax_list, List *is_min_list, List *keys)
+{
+	StringInfoData returning;
+	char		*recalc_cond;
+	ListCell	*lc;
+
+	Assert(minmax_list != NIL && is_min_list != NIL);
+	recalc_cond = get_minmax_recalc_condition_string(minmax_list, is_min_list);
+
+	initStringInfo(&returning);
+
+	appendStringInfo(&returning, "RETURNING mv.ctid AS tid, (%s) AS recalc", recalc_cond);
+	foreach (lc, keys)
+	{
+		Form_pg_attribute attr = (Form_pg_attribute) lfirst(lc);
+		char *resname = NameStr(attr->attname);
+		appendStringInfo(&returning, ", %s", quote_qualified_identifier("mv", resname));
+	}
+
+	return returning.data;
+}
+
+/*
+ * get_minmax_recalc_condition_string
+ *
+ * Build a predicate string for checking if any min/max aggregate
+ * value needs to be recalculated.
+ */
+static char *
+get_minmax_recalc_condition_string(List *minmax_list, List *is_min_list)
+{
+	StringInfoData recalc_cond;
+	ListCell	*lc1, *lc2;
+
+	initStringInfo(&recalc_cond);
+
+	Assert (list_length(minmax_list) == list_length(is_min_list));
+
+	forboth (lc1, minmax_list, lc2, is_min_list)
+	{
+		char   *resname = (char *) lfirst(lc1);
+		bool	is_min = (bool) lfirst_int(lc2);
+		char   *op_str = (is_min ? ">=" : "<=");
+
+		appendStringInfo(&recalc_cond, "%s OPERATOR(pg_catalog.%s) %s",
+			quote_qualified_identifier("mv", resname),
+			op_str,
+			quote_qualified_identifier("t", resname)
+		);
+
+		if (lnext(minmax_list, lc1))
+			appendStringInfo(&recalc_cond, " OR ");
+	}
+
+	return recalc_cond.data;
+}
+
+/*
+ * get_select_for_recalc_string
+ *
+ * Build a query to return tid and keys of tuples which need
+ * recalculation. This is used as the result of the query
+ * built by apply_old_delta.
+ */
+static char *
+get_select_for_recalc_string(List *keys)
+{
+	StringInfoData qry;
+	ListCell	*lc;
+
+	initStringInfo(&qry);
+
+	appendStringInfo(&qry, "SELECT tid");
+	foreach (lc, keys)
+	{
+		Form_pg_attribute attr = (Form_pg_attribute) lfirst(lc);
+		appendStringInfo(&qry, ", %s", NameStr(attr->attname));
+	}
+
+	appendStringInfo(&qry, " FROM updt WHERE recalc");
+
+	return qry.data;
+}
+
+/*
+ * recalc_and_set_values
+ *
+ * Recalculate tuples in a materialized from base tables and update these.
+ * The tuples which needs recalculation are specified by keys, and resnames
+ * of columns to be updated are specified by namelist. TIDs and key values
+ * are given by tuples in tuptable_recalc. Its first attribute must be TID
+ * and key values must be following this.
+ */
+static void
+recalc_and_set_values(SPITupleTable *tuptable_recalc, int64 num_tuples,
+					  List *namelist, List *keys, Relation matviewRel)
+{
+	TupleDesc   tupdesc_recalc = tuptable_recalc->tupdesc;
+	Oid		   *keyTypes = NULL, *types = NULL;
+	char	   *keyNulls = NULL, *nulls = NULL;
+	Datum	   *keyVals = NULL, *vals = NULL;
+	int			num_vals = list_length(namelist);
+	int			num_keys = list_length(keys);
+	uint64      i;
+	Oid			matviewOid;
+	char	   *matviewname;
+
+	matviewOid = RelationGetRelid(matviewRel);
+	matviewname = quote_qualified_identifier(get_namespace_name(RelationGetNamespace(matviewRel)),
+											 RelationGetRelationName(matviewRel));
+
+	/* If we have keys, initialize arrays for them. */
+	if (keys)
+	{
+		keyTypes = palloc(sizeof(Oid) * num_keys);
+		keyNulls = palloc(sizeof(char) * num_keys);
+		keyVals = palloc(sizeof(Datum) * num_keys);
+		/* a tuple contains keys to be recalculated and ctid to be updated*/
+		Assert(tupdesc_recalc->natts == num_keys + 1);
+
+		/* Types of key attributes  */
+		for (i = 0; i < num_keys; i++)
+			keyTypes[i] = TupleDescAttr(tupdesc_recalc, i + 1)->atttypid;
+	}
+
+	/* allocate memory for all attribute names and tid */
+	types = palloc(sizeof(Oid) * (num_vals + 1));
+	nulls = palloc(sizeof(char) * (num_vals + 1));
+	vals = palloc(sizeof(Datum) * (num_vals + 1));
+
+	/* For each tuple which needs recalculation */
+	for (i = 0; i < num_tuples; i++)
+	{
+		int j;
+		bool isnull;
+		SPIPlanPtr plan;
+		SPITupleTable *tuptable_newvals;
+		TupleDesc   tupdesc_newvals;
+
+		/* Set group key values as parameters if needed. */
+		if (keys)
+		{
+			for (j = 0; j < num_keys; j++)
+			{
+				keyVals[j] = SPI_getbinval(tuptable_recalc->vals[i], tupdesc_recalc, j + 2, &isnull);
+				if (isnull)
+					keyNulls[j] = 'n';
+				else
+					keyNulls[j] = ' ';
+			}
+		}
+
+		/*
+		 * Get recalculated values from base tables. The result must be
+		 * only one tuple thich contains the new values for specified keys.
+		 */
+		plan = get_plan_for_recalc(matviewOid, namelist, keys, keyTypes);
+		if (SPI_execute_plan(plan, keyVals, keyNulls, false, 0) != SPI_OK_SELECT)
+			elog(ERROR, "SPI_execute_plan");
+		if (SPI_processed != 1)
+			elog(ERROR, "SPI_execute_plan returned zero or more than one rows");
+
+		tuptable_newvals = SPI_tuptable;
+		tupdesc_newvals = tuptable_newvals->tupdesc;
+
+		Assert(tupdesc_newvals->natts == num_vals);
+
+		/* Set the new values as parameters */
+		for (j = 0; j < tupdesc_newvals->natts; j++)
+		{
+			if (i == 0)
+				types[j] = TupleDescAttr(tupdesc_newvals, j)->atttypid;
+
+			vals[j] = SPI_getbinval(tuptable_newvals->vals[0], tupdesc_newvals, j + 1, &isnull);
+			if (isnull)
+				nulls[j] = 'n';
+			else
+				nulls[j] = ' ';
+		}
+		/* Set TID of the view tuple to be updated as a parameter */
+		types[j] = TIDOID;
+		vals[j] = SPI_getbinval(tuptable_recalc->vals[i], tupdesc_recalc, 1, &isnull);
+		nulls[j] = ' ';
+
+		/* Update the view tuple to the new values */
+		plan = get_plan_for_set_values(matviewOid, matviewname, namelist, types);
+		if (SPI_execute_plan(plan, vals, nulls, false, 0) != SPI_OK_UPDATE)
+			elog(ERROR, "SPI_execute_plan");
+	}
+}
+
+
+/*
+ * get_plan_for_recalc
+ *
+ * Create or fetch a plan for recalculating value in the view's target list
+ * from base tables using the definition query of materialized view specified
+ * by matviewOid. namelist is a list of resnames of values to be recalculated.
+ *
+ * keys is a list of keys to identify tuples to be recalculated if this is not
+ * empty. KeyTypes is an array of types of keys.
+ */
+static SPIPlanPtr
+get_plan_for_recalc(Oid matviewOid, List *namelist, List *keys, Oid *keyTypes)
+{
+	MV_QueryKey hash_key;
+	SPIPlanPtr	plan;
+
+	/* Fetch or prepare a saved plan for the recalculation */
+	mv_BuildQueryKey(&hash_key, matviewOid, MV_PLAN_RECALC);
+	if ((plan = mv_FetchPreparedPlan(&hash_key)) == NULL)
+	{
+		ListCell	   *lc;
+		StringInfoData	str;
+		char   *viewdef;
+
+		/* get view definition of matview */
+		viewdef = text_to_cstring((text *) DatumGetPointer(
+					DirectFunctionCall1(pg_get_viewdef, ObjectIdGetDatum(matviewOid))));
+		/* get rid of trailing semi-colon */
+		viewdef[strlen(viewdef)-1] = '\0';
+
+		/*
+		 * Build a query string for recalculating values. This is like
+		 *
+		 *  SELECT x1, x2, x3, ... FROM ( ... view definition query ...) mv
+		 *   WHERE (key1, key2, ...) = ($1, $2, ...);
+		 */
+
+		initStringInfo(&str);
+		appendStringInfo(&str, "SELECT ");
+		foreach (lc, namelist)
+		{
+			appendStringInfo(&str, "%s", (char *) lfirst(lc));
+			if (lnext(namelist, lc))
+				appendStringInfoString(&str, ", ");
+		}
+		appendStringInfo(&str, " FROM (%s) mv", viewdef);
+
+		if (keys)
+		{
+			int		i = 1;
+			char	paramname[16];
+
+			appendStringInfo(&str, " WHERE (");
+			foreach (lc, keys)
+			{
+				Form_pg_attribute attr = (Form_pg_attribute) lfirst(lc);
+				char   *resname = NameStr(attr->attname);
+				Oid		typid = attr->atttypid;
+
+				sprintf(paramname, "$%d", i);
+				appendStringInfo(&str, "(");
+				generate_equal(&str, typid, resname, paramname);
+				appendStringInfo(&str, " OR (%s IS NULL AND %s IS NULL))",
+								 resname, paramname);
+
+				if (lnext(keys, lc))
+					appendStringInfoString(&str, " AND ");
+				i++;
+			}
+			appendStringInfo(&str, ")");
+		}
+		else
+			keyTypes = NULL;
+
+		plan = SPI_prepare(str.data, list_length(keys), keyTypes);
+		if (plan == NULL)
+			elog(ERROR, "SPI_prepare returned %s for %s", SPI_result_code_string(SPI_result), str.data);
+
+		SPI_keepplan(plan);
+		mv_HashPreparedPlan(&hash_key, plan);
+	}
+
+	return plan;
+}
+
+/*
+ * get_plan_for_set_values
+ *
+ * Create or fetch a plan for applying new values calculated by
+ * get_plan_for_recalc to a materialized view specified by matviewOid.
+ * matviewname is the name of the view.  namelist is a list of resnames
+ * of attributes to be updated, and valTypes is an array of types of the
+ * values.
+ */
+static SPIPlanPtr
+get_plan_for_set_values(Oid matviewOid, char *matviewname, List *namelist,
+						Oid *valTypes)
+{
+	MV_QueryKey	key;
+	SPIPlanPtr	plan;
+
+	/* Fetch or prepare a saved plan for the real check */
+	mv_BuildQueryKey(&key, matviewOid, MV_PLAN_SET_VALUE);
+	if ((plan = mv_FetchPreparedPlan(&key)) == NULL)
+	{
+		ListCell	  *lc;
+		StringInfoData str;
+		int		i;
+
+		/*
+		 * Build a query string for applying min/max values. This is like
+		 *
+		 *  UPDATE matviewname AS mv
+		 *   SET (x1, x2, x3, x4) = ($1, $2, $3, $4)
+		 *   WHERE ctid = $5;
+		 */
+
+		initStringInfo(&str);
+		appendStringInfo(&str, "UPDATE %s AS mv SET (", matviewname);
+		foreach (lc, namelist)
+		{
+			appendStringInfo(&str, "%s", (char *) lfirst(lc));
+			if (lnext(namelist, lc))
+				appendStringInfoString(&str, ", ");
+		}
+		appendStringInfo(&str, ") = ROW(");
+
+		for (i = 1; i <= list_length(namelist); i++)
+			appendStringInfo(&str, "%s$%d", (i==1 ? "" : ", "), i);
+
+		appendStringInfo(&str, ") WHERE ctid OPERATOR(pg_catalog.=) $%d", i);
+
+		plan = SPI_prepare(str.data, list_length(namelist) + 1, valTypes);
+		if (plan == NULL)
+			elog(ERROR, "SPI_prepare returned %s for %s", SPI_result_code_string(SPI_result), str.data);
+
+		SPI_keepplan(plan);
+		mv_HashPreparedPlan(&key, plan);
+	}
+
+	return plan;
+}
+
 /*
  * generate_equals
  *
@@ -2784,6 +3300,13 @@ mv_InitHashTables(void)
 {
 	HASHCTL		ctl;
 
+	memset(&ctl, 0, sizeof(ctl));
+	ctl.keysize = sizeof(MV_QueryKey);
+	ctl.entrysize = sizeof(MV_QueryHashEntry);
+	mv_query_cache = hash_create("MV query cache",
+								 MV_INIT_QUERYHASHSIZE,
+								 &ctl, HASH_ELEM | HASH_BLOBS);
+
 	memset(&ctl, 0, sizeof(ctl));
 	ctl.keysize = sizeof(Oid);
 	ctl.entrysize = sizeof(MV_TriggerHashEntry);
@@ -2792,6 +3315,109 @@ mv_InitHashTables(void)
 								 &ctl, HASH_ELEM | HASH_BLOBS);
 }
 
+/*
+ * mv_FetchPreparedPlan
+ */
+static SPIPlanPtr
+mv_FetchPreparedPlan(MV_QueryKey *key)
+{
+	MV_QueryHashEntry *entry;
+	SPIPlanPtr	plan;
+
+	/*
+	 * On the first call initialize the hashtable
+	 */
+	if (!mv_query_cache)
+		mv_InitHashTables();
+
+	/*
+	 * Lookup for the key
+	 */
+	entry = (MV_QueryHashEntry *) hash_search(mv_query_cache,
+											  (void *) key,
+											  HASH_FIND, NULL);
+	if (entry == NULL)
+		return NULL;
+
+	/*
+	 * Check whether the plan is still valid.  If it isn't, we don't want to
+	 * simply rely on plancache.c to regenerate it; rather we should start
+	 * from scratch and rebuild the query text too.  This is to cover cases
+	 * such as table/column renames.  We depend on the plancache machinery to
+	 * detect possible invalidations, though.
+	 *
+	 * CAUTION: this check is only trustworthy if the caller has already
+	 * locked both materialized views and base tables.
+	 *
+	 * Also, check whether the search_path is still the same as when we made it.
+	 * If it isn't, we need to rebuild the query text because the result of
+	 * pg_ivm_get_viewdef() will change.
+	 */
+	plan = entry->plan;
+	if (plan && SPI_plan_is_valid(plan) &&
+		OverrideSearchPathMatchesCurrent(entry->search_path))
+		return plan;
+
+	/*
+	 * Otherwise we might as well flush the cached plan now, to free a little
+	 * memory space before we make a new one.
+	 */
+	if (plan)
+		SPI_freeplan(plan);
+	if (entry->search_path)
+		pfree(entry->search_path);
+
+	entry->plan = NULL;
+	entry->search_path = NULL;
+
+	return NULL;
+}
+
+/*
+ * mv_HashPreparedPlan
+ *
+ * Add another plan to our private SPI query plan hashtable.
+ */
+static void
+mv_HashPreparedPlan(MV_QueryKey *key, SPIPlanPtr plan)
+{
+	MV_QueryHashEntry *entry;
+	bool		found;
+
+	/*
+	 * On the first call initialize the hashtable
+	 */
+	if (!mv_query_cache)
+		mv_InitHashTables();
+
+	/*
+	 * Add the new plan.  We might be overwriting an entry previously found
+	 * invalid by mv_FetchPreparedPlan.
+	 */
+	entry = (MV_QueryHashEntry *) hash_search(mv_query_cache,
+											  (void *) key,
+											  HASH_ENTER, &found);
+	Assert(!found || entry->plan == NULL);
+	entry->plan = plan;
+	entry->search_path = GetOverrideSearchPath(TopMemoryContext);
+}
+
+/*
+ * mv_BuildQueryKey
+ *
+ * Construct a hashtable key for a prepared SPI plan for IVM.
+ */
+static void
+mv_BuildQueryKey(MV_QueryKey *key, Oid matview_id, int32 query_type)
+{
+	/*
+	 * We assume struct MV_QueryKey contains no padding bytes, else we'd need
+	 * to use memset to clear them.
+	 */
+	key->matview_id = matview_id;
+	key->query_type = query_type;
+}
+
 /*
  * AtAbort_IVM
  *
-- 
2.25.1


--Multipart=_Thu__1_Jun_2023_23_59_09_+0900_/G5+8nG46.f1T42K
Content-Type: text/x-diff;
 name="v28-0010-Add-regression-tests-for-Incremental-View-Mainte.patch"
Content-Disposition: attachment;
 filename="v28-0010-Add-regression-tests-for-Incremental-View-Mainte.patch"
Content-Transfer-Encoding: 7bit



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* [PATCH v2 1/2] Do not lock tables in get_tables_to_repack().
@ 2026-06-16 06:49 ChangAo Chen <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: ChangAo Chen @ 2026-06-16 06:49 UTC (permalink / raw)

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index faa07d1a118..2879c8af574 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2169,22 +2169,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2192,7 +2179,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2201,10 +2187,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2228,45 +2211,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2279,7 +2237,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2357,15 +2315,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.47.3


--op6mnexl7cn72cto
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename=v2-0002-fixups.patch



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* Do not lock tables in get_tables_to_repack
@ 2026-06-16 07:34 =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-06-27 19:56 ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
  2026-07-07 16:53 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  0 siblings, 2 replies; 204+ messages in thread

From: =?utf-8?B?Y2NhNTUwNw==?= @ 2026-06-16 07:34 UTC (permalink / raw)
  To: =?utf-8?B?cGdzcWwtaGFja2Vycw==?= <[email protected]>

Hi hackers,

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

Thoughts?

--
Regards,
ChangAo Chen


Attachments:

  [application/octet-stream] v1-0001-Do-not-lock-tables-in-get_tables_to_repack.patch (5.4K, ../../[email protected]/2-v1-0001-Do-not-lock-tables-in-get_tables_to_repack.patch)
  download | inline diff:
From fa5c3073f2f41cf3c8ab7c9663b681e6140a4824 Mon Sep 17 00:00:00 2001
From: ChangAo Chen <[email protected]>
Date: Tue, 16 Jun 2026 14:49:49 +0800
Subject: [PATCH v1] Do not lock tables in get_tables_to_repack().

When doing a whole database repack, we build a list of repackable
tables and take a lock on them to prevent concurrent drops. But
concurrent drops can always happen after we build the list because
we process each table in a separate transaction. The
ConditionalLockRelationOid() also makes the default behavior like
SKIP_LOCKED, which is unexpected.

To remove the locks, we need to make repack_is_permitted_for_relation()
handles concurrent drops correctly: it should not report an error
when failing to search the syscache in pg_class_aclcheck(). Use
pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
check the return value of get_rel_name().

While at it, replace relation_close() with table_close() to match
the table_open().
---
 src/backend/commands/repack.c | 67 ++++++++++-------------------------
 1 file changed, 19 insertions(+), 48 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index ec100e3eef5..6f25effeed2 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -2159,22 +2159,9 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			index = (Form_pg_index) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the index's table, to ensure it
-			 * doesn't go away while we collect the list.  If we cannot, just
-			 * disregard it.  Be sure to release this if we ultimately decide
-			 * not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(index->indrelid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists; skip if not */
 			classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
 			if (!HeapTupleIsValid(classtup))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 			classForm = (Form_pg_class) GETSTRUCT(classtup);
 
 			/* Skip temp relations belonging to other sessions */
@@ -2182,7 +2169,6 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 				!isTempOrTempToastNamespace(classForm->relnamespace))
 			{
 				ReleaseSysCache(classtup);
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
 			}
 
@@ -2191,10 +2177,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(index->indrelid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2218,45 +2201,20 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			class = (Form_pg_class) GETSTRUCT(tuple);
 
-			/*
-			 * Try to obtain a light lock on the table, to ensure it doesn't
-			 * go away while we collect the list.  If we cannot, just
-			 * disregard the table.  Be sure to release this if we ultimately
-			 * decide not to process the table!
-			 */
-			if (!ConditionalLockRelationOid(class->oid, AccessShareLock))
-				continue;
-
-			/* Verify that the table still exists */
-			if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(class->oid)))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
-				continue;
-			}
-
 			/* Can only process plain tables and matviews */
 			if (class->relkind != RELKIND_RELATION &&
 				class->relkind != RELKIND_MATVIEW)
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Skip temp relations belonging to other sessions */
 			if (class->relpersistence == RELPERSISTENCE_TEMP &&
 				!isTempOrTempToastNamespace(class->relnamespace))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
 												  GetUserId()))
-			{
-				UnlockRelationOid(class->oid, AccessShareLock);
 				continue;
-			}
 
 			/* Use a permanent memory context for the result list */
 			oldcxt = MemoryContextSwitchTo(permcxt);
@@ -2269,7 +2227,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 	}
 
 	table_endscan(scan);
-	relation_close(catalog, AccessShareLock);
+	table_close(catalog, AccessShareLock);
 
 	return rtcs;
 }
@@ -2347,15 +2305,28 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 static bool
 repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 {
+	bool		is_missing = false;
+
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
+	if (pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing) == ACLCHECK_OK)
 		return true;
 
-	ereport(WARNING,
-			errmsg("permission denied to execute %s on \"%s\", skipping it",
-				   RepackCommandAsString(cmd),
-				   get_rel_name(relid)));
+	/* Report a warning if the relation still exists. */
+	if (!is_missing)
+	{
+		char	   *relname;
+
+		relname = get_rel_name(relid);
+		if (relname != NULL)
+		{
+			ereport(WARNING,
+					errmsg("permission denied to execute %s on \"%s\", skipping it",
+						   RepackCommandAsString(cmd), relname));
+
+			pfree(relname);
+		}
+	}
 
 	return false;
 }
-- 
2.34.1



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* Re: Do not lock tables in get_tables_to_repack
  2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
@ 2026-06-27 19:56 ` Bharath Rupireddy <[email protected]>
  1 sibling, 0 replies; 204+ messages in thread

From: Bharath Rupireddy @ 2026-06-27 19:56 UTC (permalink / raw)
  To: cca5507 <[email protected]>; +Cc: pgsql-hackers <[email protected]>; Antonin Houska <[email protected]>; Alvaro Herrera <[email protected]>

Hi,

On Tue, Jun 16, 2026 at 12:35 AM cca5507 <[email protected]> wrote:
>
> Hi hackers,
>
> When doing a whole database repack, we build a list of repackable
> tables and take a lock on them to prevent concurrent drops. But
> concurrent drops can always happen after we build the list because
> we process each table in a separate transaction. The
> ConditionalLockRelationOid() also makes the default behavior like
> SKIP_LOCKED, which is unexpected.
>
> To remove the locks, we need to make repack_is_permitted_for_relation()
> handles concurrent drops correctly: it should not report an error
> when failing to search the syscache in pg_class_aclcheck(). Use
> pg_class_aclcheck_ext() instead to detect a concurrent drop. Also
> check the return value of get_rel_name().
>
> Thoughts?

I don't have a strong opinion on fixing this for REPACK. For vacuum,
we wanted to get consistent behavior across all modes of invoking it
[1]. Whether to handle concurrent drops for REPACK depends on how long
it spends scanning pg_index/pg_class in get_tables_to_repack. Also,
vacuum is more commonly run database-wide (against all tables), and
without field experience showing this is a real problem for REPACK,
I'm not sure the fix is needed. That said, others may have a different
take - adding the REPACK authors here for their input.

[1] https://www.postgresql.org/message-id/CALj2ACUbhDFJWSwiyoUxXED2S2fr9Xis%3D08Rnjq53UzBE4FvzA%40mail.g...

--
Bharath Rupireddy
Amazon Web Services: https://aws.amazon.com





^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* Re: Do not lock tables in get_tables_to_repack
  2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
@ 2026-07-07 16:53 ` Álvaro Herrera <[email protected]>
  2026-07-08 02:36   ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  1 sibling, 1 reply; 204+ messages in thread

From: Álvaro Herrera @ 2026-07-07 16:53 UTC (permalink / raw)
  To: cca5507 <[email protected]>; +Cc: pgsql-hackers <[email protected]>

On 2026-Jun-16, cca5507 wrote:

> Hi hackers,
> 
> When doing a whole database repack, we build a list of repackable
> tables and take a lock on them to prevent concurrent drops. But
> concurrent drops can always happen after we build the list because
> we process each table in a separate transaction.

Not only that.  We have actually three ways to obtain the list of tables
to repack, and only one of these obtains the locks.  So this code is
internally inconsistent.  I agree that we should do something like your
patch.  I wanted to be a little more defensive though; how about the
attached?

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/


^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* Re: Do not lock tables in get_tables_to_repack
  2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-07 16:53 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
@ 2026-07-08 02:36   ` =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-10 14:22     ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  0 siblings, 1 reply; 204+ messages in thread

From: =?utf-8?B?Y2NhNTUwNw==?= @ 2026-07-08 02:36 UTC (permalink / raw)
  To: =?utf-8?B?w4FsdmFybyBIZXJyZXJh?= <[email protected]>; +Cc: =?utf-8?B?cGdzcWwtaGFja2Vycw==?= <[email protected]>

> > Hi hackers,
> > 
> > When doing a whole database repack, we build a list of repackable
> > tables and take a lock on them to prevent concurrent drops. But
> > concurrent drops can always happen after we build the list because
> > we process each table in a separate transaction.
> 
> Not only that.  We have actually three ways to obtain the list of tables
> to repack, and only one of these obtains the locks.  So this code is
> internally inconsistent.  I agree that we should do something like your
> patch.  I wanted to be a little more defensive though; how about the
> attached?

-                       classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
+                       classtup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(index->indrelid));

Do we really need to copy it? We hold a refcount on it so it won't be freed
until we release it. Otherwise LGTM.

--
Regards,
ChangAo Chen


^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* Re: Do not lock tables in get_tables_to_repack
  2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-07 16:53 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  2026-07-08 02:36   ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
@ 2026-07-10 14:22     ` Álvaro Herrera <[email protected]>
  2026-07-10 16:03       ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
  0 siblings, 1 reply; 204+ messages in thread

From: Álvaro Herrera @ 2026-07-10 14:22 UTC (permalink / raw)
  To: cca5507 <[email protected]>; +Cc: pgsql-hackers <[email protected]>

On 2026-Jul-08, cca5507 wrote:

> -                       classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
> +                       classtup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(index->indrelid));
> 
> Do we really need to copy it? We hold a refcount on it so it won't be freed
> until we release it. Otherwise LGTM.

Yeah, I guess it doesn't matter.  I have removed the copy and updated
some comments.  I also realized that there are some places where we
weren't dealing correctly with the possibility that the relation goes
away, or is replaced with something different, so I added that too.

While looking at it I also realized that get_tables_to_repack_partitioned
is likewise not careful enough about it: we do IndexGetRelation(, false)
which fails hard if the pg_index tuple cannot be found, which is the
wrong thing to do.

At the same time, it's annoying that half of the code that clearly
belongs in that routine is actually in ExecRepack().  I moved that to
where it rightfully belongs.  (The only somewhat annoying thing is that
we have to NULL-out the Relation pointer after returning; but that's not
*too* bad IMO.)

Any opinions on this?

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"No me acuerdo, pero no es cierto.  No es cierto, y si fuera cierto,
 no me acuerdo."                 (Augusto Pinochet a una corte de justicia)


^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* Re: Do not lock tables in get_tables_to_repack
  2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-07 16:53 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  2026-07-08 02:36   ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-10 14:22     ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
@ 2026-07-10 16:03       ` Bharath Rupireddy <[email protected]>
  2026-07-10 17:34         ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
  0 siblings, 1 reply; 204+ messages in thread

From: Bharath Rupireddy @ 2026-07-10 16:03 UTC (permalink / raw)
  To: Álvaro Herrera <[email protected]>; +Cc: cca5507 <[email protected]>; pgsql-hackers <[email protected]>

Hi,

On Fri, Jul 10, 2026 at 7:22 AM Álvaro Herrera <[email protected]> wrote:
>
> On 2026-Jul-08, cca5507 wrote:
>
> > -                       classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(index->indrelid));
> > +                       classtup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(index->indrelid));
> >
> > Do we really need to copy it? We hold a refcount on it so it won't be freed
> > until we release it. Otherwise LGTM.

Thanks for committing this.

Here is my overall take. Even before this commit, a database-wide
REPACK does not error on a concurrently dropped table.
get_tables_to_repack takes a brief lock on each table before the ACL
check, which blocks a concurrent drop while the list is being built.
Later each table is re-opened under its lock and skipped if it is
already gone. So the brief lock is not needed for correctness. What it
does is let an unprivileged user lock relations it may not even be
allowed to repack, including system catalogs, before we have checked
its privileges. I am fine with removing the lock as the commit did.

I would also like to tighten repack_is_permitted_for_relation so a
caller that holds a lock still errors out on a missing relation
instead of skipping it silently
(https://www.postgresql.org/message-id/akPhEffRipH4isWF%40nathan).
Attached as a follow-up patch. Please have a look.

> Yeah, I guess it doesn't matter.  I have removed the copy and updated
> some comments.  I also realized that there are some places where we
> weren't dealing correctly with the possibility that the relation goes
> away, or is replaced with something different, so I added that too.

I agree that the SearchSysCacheCopy1 in v2-0002 adds no benefit. Since
no lock is held on the relation, there is no point in copying the
syscache tuple.

> While looking at it I also realized that get_tables_to_repack_partitioned
> is likewise not careful enough about it: we do IndexGetRelation(, false)
> which fails hard if the pg_index tuple cannot be found, which is the
> wrong thing to do.
>
> At the same time, it's annoying that half of the code that clearly
> belongs in that routine is actually in ExecRepack().  I moved that to
> where it rightfully belongs.  (The only somewhat annoying thing is that
> we have to NULL-out the Relation pointer after returning; but that's not
> *too* bad IMO.)
>
> Any opinions on this?

I will take a closer look at this in a bit.

--
Bharath Rupireddy
Amazon Web Services: https://aws.amazon.com


Attachments:

  [application/octet-stream] v1-0001-Tighten-ACL-check-in-repack_is_permitted_for_rela.patch (5.1K, ../../CALj2ACX3pyuRS8++6L20cJUMRTf_qbbVp69J1btJ3y6=77e5gw@mail.gmail.com/2-v1-0001-Tighten-ACL-check-in-repack_is_permitted_for_rela.patch)
  download | inline diff:
From 6729b2f14ed623a8b38f5a530b8c85c96bfd5b40 Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <[email protected]>
Date: Fri, 10 Jul 2026 15:42:47 +0000
Subject: [PATCH v1] Tighten ACL check in repack_is_permitted_for_relation()

Commit c71d43025d7 made repack_is_permitted_for_relation() use
_ext() and skip a concurrently dropped relation silently. That is
fine for the callers that hold no lock on the relation, but it is
applied unconditionally, including where we may already hold a
lock on the relation whose ACL is checked. In that case missing a
relation is not fine, so this made the code more brittle: a
missing relation there would indicate a bug and should error out
rather than be skipped silently.

Add a missing_ok flag so the silent skip is done only where no
lock is held. Callers that hold a lock pass false and still error
out on a missing relation.
---
 src/backend/commands/repack.c | 38 ++++++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 02883fe34a4..b09be65da3b 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -172,8 +172,8 @@ static List *get_tables_to_repack(RepackCommand cmd, bool usingindex,
 static List *get_tables_to_repack_partitioned(RepackCommand cmd,
 											  Oid relid, bool rel_is_index,
 											  MemoryContext permcxt);
-static bool repack_is_permitted_for_relation(RepackCommand cmd,
-											 Oid relid, Oid userid);
+static bool repack_is_permitted_for_relation(RepackCommand cmd, Oid relid,
+											 Oid userid, bool missing_ok);
 
 static void apply_concurrent_changes(BufFile *file, ChangeContext *chgcxt);
 static void apply_concurrent_insert(Relation rel, TupleTableSlot *slot,
@@ -724,7 +724,7 @@ cluster_rel_recheck(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Assert(CheckRelationLockedByMe(OldHeap, lmode, false));
 
 	/* Check that the user still has privileges for the relation */
-	if (!repack_is_permitted_for_relation(cmd, tableOid, userid))
+	if (!repack_is_permitted_for_relation(cmd, tableOid, userid, false))
 	{
 		relation_close(OldHeap, lmode);
 		return false;
@@ -2198,7 +2198,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, index->indrelid,
-												  GetUserId()))
+												  GetUserId(), true))
 				continue;
 
 			/* Use a permanent memory context for the result list */
@@ -2235,7 +2235,7 @@ get_tables_to_repack(RepackCommand cmd, bool usingindex, MemoryContext permcxt)
 
 			/* noisily skip rels which the user can't process */
 			if (!repack_is_permitted_for_relation(cmd, class->oid,
-												  GetUserId()))
+												  GetUserId(), true))
 				continue;
 
 			/* Use a permanent memory context for the result list */
@@ -2304,7 +2304,7 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 		 * leaf partition despite having them on the partitioned table.  Skip
 		 * if so.
 		 */
-		if (!repack_is_permitted_for_relation(cmd, table_oid, GetUserId()))
+		if (!repack_is_permitted_for_relation(cmd, table_oid, GetUserId(), true))
 			continue;
 
 		/* Use a permanent memory context for the result list */
@@ -2321,16 +2321,21 @@ get_tables_to_repack_partitioned(RepackCommand cmd, Oid relid,
 
 
 /*
- * Return whether userid has privileges to execute REPACK on relid.
+ * Check whether the passed-in user has privileges to execute REPACK on the
+ * relation.
  *
- * Caller may not have a lock on the relation, so it could have been
- * dropped concurrently.  In that case, silently return false.
+ * missing_ok should be passed only by callers that hold no lock on the
+ * relation, where a concurrent drop is possible and fine to skip. A caller
+ * that holds a lock must not pass it: there a missing relation would indicate
+ * a bug and should error out rather than be silently skipped.
  *
  * If the relation does exist but the user doesn't have the required
- * privs, emit a WARNING and return false.  Otherwise, return true.
+ * privileges, emit a WARNING and return false to let the caller
+ * decide what to do with this relation.
  */
 static bool
-repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
+repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid,
+								 bool missing_ok)
 {
 	bool		is_missing = false;
 	AclResult	result;
@@ -2338,9 +2343,18 @@ repack_is_permitted_for_relation(RepackCommand cmd, Oid relid, Oid userid)
 
 	Assert(cmd == REPACK_COMMAND_CLUSTER || cmd == REPACK_COMMAND_REPACK);
 
-	result = pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN, &is_missing);
+	result = pg_class_aclcheck_ext(relid, userid, ACL_MAINTAIN,
+								   missing_ok ? &is_missing : NULL);
+
+	/*
+	 * If the relation was concurrently dropped, nothing to do. Note that this
+	 * is only reachable when the caller specified missing_ok.
+	 */
 	if (is_missing)
+	{
+		Assert(missing_ok);
 		return false;
+	}
 
 	if (result == ACLCHECK_OK)
 		return true;
-- 
2.47.3



^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* Re: Do not lock tables in get_tables_to_repack
  2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-07 16:53 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  2026-07-08 02:36   ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-10 14:22     ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  2026-07-10 16:03       ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
@ 2026-07-10 17:34         ` Bharath Rupireddy <[email protected]>
  2026-07-11 14:50           ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  0 siblings, 1 reply; 204+ messages in thread

From: Bharath Rupireddy @ 2026-07-10 17:34 UTC (permalink / raw)
  To: Álvaro Herrera <[email protected]>; +Cc: cca5507 <[email protected]>; pgsql-hackers <[email protected]>

Hi,

On Fri, Jul 10, 2026 at 9:03 AM Bharath Rupireddy
<[email protected]> wrote:
>
> > While looking at it I also realized that get_tables_to_repack_partitioned
> > is likewise not careful enough about it: we do IndexGetRelation(, false)
> > which fails hard if the pg_index tuple cannot be found, which is the
> > wrong thing to do.

Agreed. For a single-level partitioned table, dropping a leaf blocks
on the parent's AccessExclusiveLock, which REPACK holds, so the leaf
can't go away mid-build. But for a multi-level table, REPACK holds a
lock only on the top parent, so a lower-level leaf whose immediate
parent is an intermediate table isn't protected and can be dropped
concurrently. So IndexGetRelation(, false) failing hard there is
indeed the wrong thing.

> > At the same time, it's annoying that half of the code that clearly
> > belongs in that routine is actually in ExecRepack().  I moved that to
> > where it rightfully belongs.

+1, that's a good cleanup. That code clearly belongs in
get_tables_to_repack_partitioned().

>> (The only somewhat annoying thing is that
> > we have to NULL-out the Relation pointer after returning; but that's not
> > *too* bad IMO.)

That's fine. We already NULL out rel after
get_tables_to_repack_partitioned() today, so the patch isn't adding
anything new there. Relying on a non-NULL return from
process_single_relation() to mean partitioned table is a little
indirect on first read, but the comments explains it well, and I
wouldn't complicate the code to avoid it.

> > Any opinions on this?
>
> I will take a closer look at this in a bit.

Patch looks good to me. One nit:

+ table_oid = IndexGetRelation(child_oid, true);
+ if (!OidIsValid(table_oid))
+ continue;

How about a short comment on why this is needed even with a lock on
the parent, since that lock doesn't cover lower-level leaves in a
multi-level partition tree?

--
Bharath Rupireddy
Amazon Web Services: https://aws.amazon.com





^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* Re: Do not lock tables in get_tables_to_repack
  2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-07 16:53 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  2026-07-08 02:36   ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-10 14:22     ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  2026-07-10 16:03       ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
  2026-07-10 17:34         ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
@ 2026-07-11 14:50           ` =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-20 10:19             ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  0 siblings, 1 reply; 204+ messages in thread

From: =?utf-8?B?Y2NhNTUwNw==?= @ 2026-07-11 14:50 UTC (permalink / raw)
  To: =?utf-8?B?QmhhcmF0aCBSdXBpcmVkZHk=?= <[email protected]>; =?utf-8?B?w4FsdmFybyBIZXJyZXJh?= <[email protected]>; +Cc: =?utf-8?B?cGdzcWwtaGFja2Vycw==?= <[email protected]>

> > > Any opinions on this?
> >
> > I will take a closer look at this in a bit.
> 
> Patch looks good to me. One nit:
> 
> + table_oid = IndexGetRelation(child_oid, true);
> + if (!OidIsValid(table_oid))
> + continue;
> 
> How about a short comment on why this is needed even with a lock on
> the parent, since that lock doesn't cover lower-level leaves in a
> multi-level partition tree?

I think it's worth a comment, too. Patch LGTM.

--
Regards,
ChangAo Chen


^ permalink  raw  reply  [nested|flat] 204+ messages in thread

* Re: Do not lock tables in get_tables_to_repack
  2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-07 16:53 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  2026-07-08 02:36   ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
  2026-07-10 14:22     ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
  2026-07-10 16:03       ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
  2026-07-10 17:34         ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
  2026-07-11 14:50           ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
@ 2026-07-20 10:19             ` Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 204+ messages in thread

From: Álvaro Herrera @ 2026-07-20 10:19 UTC (permalink / raw)
  To: cca5507 <[email protected]>; +Cc: Bharath Rupireddy <[email protected]>; pgsql-hackers <[email protected]>

On 2026-Jul-11, cca5507 wrote:

> Bharath Rupireddy wrote:

> > + table_oid = IndexGetRelation(child_oid, true);
> > + if (!OidIsValid(table_oid))
> > + continue;
> > 
> > How about a short comment on why this is needed even with a lock on
> > the parent, since that lock doesn't cover lower-level leaves in a
> > multi-level partition tree?
> 
> I think it's worth a comment, too. Patch LGTM.

Thanks, added that and pushed.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"Puedes vivir sólo una vez, pero si lo haces bien, una vez es suficiente"






^ permalink  raw  reply  [nested|flat] 204+ messages in thread


end of thread, other threads:[~2026-07-20 10:19 UTC | newest]

Thread overview: 204+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2023-05-31 11:58 [PATCH v28 09/11] Add support for min/max aggregates for IVM Yugo Nagata <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 06:49 [PATCH v2 1/2] Do not lock tables in get_tables_to_repack(). ChangAo Chen <[email protected]>
2026-06-16 07:34 Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
2026-06-27 19:56 ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
2026-07-07 16:53 ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
2026-07-08 02:36   ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
2026-07-10 14:22     ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>
2026-07-10 16:03       ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
2026-07-10 17:34         ` Re: Do not lock tables in get_tables_to_repack Bharath Rupireddy <[email protected]>
2026-07-11 14:50           ` Re: Do not lock tables in get_tables_to_repack =?utf-8?B?Y2NhNTUwNw==?= <[email protected]>
2026-07-20 10:19             ` Re: Do not lock tables in get_tables_to_repack Álvaro Herrera <[email protected]>

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