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* [PATCH v11 4/7] Row pattern recognition patch (executor).
@ 2023-11-08 06:57 Tatsuo Ishii <[email protected]>
0 siblings, 0 replies; 85+ messages in thread
From: Tatsuo Ishii @ 2023-11-08 06:57 UTC (permalink / raw)
---
src/backend/executor/nodeWindowAgg.c | 1420 +++++++++++++++++++++++++-
src/backend/utils/adt/windowfuncs.c | 37 +-
src/include/catalog/pg_proc.dat | 6 +
src/include/nodes/execnodes.h | 26 +
4 files changed, 1476 insertions(+), 13 deletions(-)
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index 77724a6daa..ea5e73c969 100644
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -36,6 +36,7 @@
#include "access/htup_details.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_aggregate.h"
+#include "catalog/pg_collation_d.h"
#include "catalog/pg_proc.h"
#include "executor/executor.h"
#include "executor/nodeWindowAgg.h"
@@ -48,6 +49,7 @@
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/datum.h"
+#include "utils/fmgroids.h"
#include "utils/expandeddatum.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
@@ -159,6 +161,40 @@ typedef struct WindowStatePerAggData
bool restart; /* need to restart this agg in this cycle? */
} WindowStatePerAggData;
+/*
+ * Set of StringInfo. Used in RPR.
+ */
+typedef struct StringSet {
+ StringInfo *str_set;
+ Size set_size; /* current array allocation size in number of items */
+ int set_index; /* current used size */
+} StringSet;
+
+/*
+ * Allowed subsequent PATTERN variables positions.
+ * Used in RPR.
+ *
+ * pos represents the pattern variable defined order in DEFINE caluase. For
+ * example. "DEFINE START..., UP..., DOWN ..." and "PATTERN START UP DOWN UP"
+ * will create:
+ * VariablePos[0].pos[0] = 0; START
+ * VariablePos[1].pos[0] = 1; UP
+ * VariablePos[1].pos[1] = 3; UP
+ * VariablePos[2].pos[0] = 2; DOWN
+ *
+ * Note that UP has two pos because UP appears in PATTERN twice.
+ *
+ * By using this strucrture, we can know which pattern variable can be followed
+ * by which pattern variable(s). For example, START can be followed by UP and
+ * DOWN since START's pos is 0, and UP's pos is 1 or 3, DOWN's pos is 2.
+ * DOWN can be followed by UP since UP's pos is either 1 or 3.
+ *
+ */
+#define NUM_ALPHABETS 26 /* we allow [a-z] variable initials */
+typedef struct VariablePos {
+ int pos[NUM_ALPHABETS]; /* postion(s) in PATTERN */
+} VariablePos;
+
static void initialize_windowaggregate(WindowAggState *winstate,
WindowStatePerFunc perfuncstate,
WindowStatePerAgg peraggstate);
@@ -182,8 +218,9 @@ static void begin_partition(WindowAggState *winstate);
static void spool_tuples(WindowAggState *winstate, int64 pos);
static void release_partition(WindowAggState *winstate);
-static int row_is_in_frame(WindowAggState *winstate, int64 pos,
+static int row_is_in_frame(WindowAggState *winstate, int64 pos,
TupleTableSlot *slot);
+
static void update_frameheadpos(WindowAggState *winstate);
static void update_frametailpos(WindowAggState *winstate);
static void update_grouptailpos(WindowAggState *winstate);
@@ -195,9 +232,42 @@ static Datum GetAggInitVal(Datum textInitVal, Oid transtype);
static bool are_peers(WindowAggState *winstate, TupleTableSlot *slot1,
TupleTableSlot *slot2);
-static bool window_gettupleslot(WindowObject winobj, int64 pos,
- TupleTableSlot *slot);
+static int WinGetSlotInFrame(WindowObject winobj, TupleTableSlot *slot,
+ int relpos, int seektype, bool set_mark,
+ bool *isnull, bool *isout);
+static bool window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot);
+
+static void attno_map(Node *node);
+static bool attno_map_walker(Node *node, void *context);
+static int row_is_in_reduced_frame(WindowObject winobj, int64 pos);
+static bool rpr_is_defined(WindowAggState *winstate);
+
+static void create_reduced_frame_map(WindowAggState *winstate);
+static int get_reduced_frame_map(WindowAggState *winstate, int64 pos);
+static void register_reduced_frame_map(WindowAggState *winstate, int64 pos, int val);
+static void clear_reduced_frame_map(WindowAggState *winstate);
+static void update_reduced_frame(WindowObject winobj, int64 pos);
+
+static int64 evaluate_pattern(WindowObject winobj, int64 current_pos,
+ char *vname, StringInfo encoded_str, bool *result);
+
+static bool get_slots(WindowObject winobj, int64 current_pos);
+
+static int search_str_set(char *pattern, StringSet *str_set, VariablePos *variable_pos);
+static char pattern_initial(WindowAggState *winstate, char *vname);
+static int do_pattern_match(char *pattern, char *encoded_str);
+
+static StringSet *string_set_init(void);
+static void string_set_add(StringSet *string_set, StringInfo str);
+static StringInfo string_set_get(StringSet *string_set, int index);
+static int string_set_get_size(StringSet *string_set);
+static void string_set_discard(StringSet *string_set);
+static VariablePos *variable_pos_init(void);
+static void variable_pos_register(VariablePos *variable_pos, char initial, int pos);
+static bool variable_pos_compare(VariablePos *variable_pos, char initial1, char initial2);
+static int variable_pos_fetch(VariablePos *variable_pos, char initial, int index);
+static void variable_pos_discard(VariablePos *variable_pos);
/*
* initialize_windowaggregate
@@ -673,6 +743,7 @@ eval_windowaggregates(WindowAggState *winstate)
WindowObject agg_winobj;
TupleTableSlot *agg_row_slot;
TupleTableSlot *temp_slot;
+ bool agg_result_isnull;
numaggs = winstate->numaggs;
if (numaggs == 0)
@@ -778,6 +849,9 @@ eval_windowaggregates(WindowAggState *winstate)
* Note that we don't strictly need to restart in the last case, but if
* we're going to remove all rows from the aggregation anyway, a restart
* surely is faster.
+ *
+ * - if RPR is enabled and skip mode is SKIP TO NEXT ROW,
+ * we restart aggregation too.
*----------
*/
numaggs_restart = 0;
@@ -788,8 +862,11 @@ eval_windowaggregates(WindowAggState *winstate)
(winstate->aggregatedbase != winstate->frameheadpos &&
!OidIsValid(peraggstate->invtransfn_oid)) ||
(winstate->frameOptions & FRAMEOPTION_EXCLUSION) ||
- winstate->aggregatedupto <= winstate->frameheadpos)
+ winstate->aggregatedupto <= winstate->frameheadpos ||
+ (rpr_is_defined(winstate) &&
+ winstate->rpSkipTo == ST_NEXT_ROW))
{
+ elog(DEBUG1, "peraggstate->restart is set");
peraggstate->restart = true;
numaggs_restart++;
}
@@ -861,8 +938,10 @@ eval_windowaggregates(WindowAggState *winstate)
* If we created a mark pointer for aggregates, keep it pushed up to frame
* head, so that tuplestore can discard unnecessary rows.
*/
+#ifdef NOT_USED
if (agg_winobj->markptr >= 0)
WinSetMarkPosition(agg_winobj, winstate->frameheadpos);
+#endif
/*
* Now restart the aggregates that require it.
@@ -917,6 +996,29 @@ eval_windowaggregates(WindowAggState *winstate)
{
winstate->aggregatedupto = winstate->frameheadpos;
ExecClearTuple(agg_row_slot);
+
+ /*
+ * If RPR is defined, we do not use aggregatedupto_nonrestarted. To
+ * avoid assertion failure below, we reset aggregatedupto_nonrestarted
+ * to frameheadpos.
+ */
+ if (rpr_is_defined(winstate))
+ aggregatedupto_nonrestarted = winstate->frameheadpos;
+ }
+
+ agg_result_isnull = false;
+ /* RPR is defined? */
+ if (rpr_is_defined(winstate))
+ {
+ /*
+ * If the skip mode is SKIP TO PAST LAST ROW and we already know that
+ * current row is a skipped row, we don't need to accumulate rows,
+ * just return NULL. Note that for unamtched row, we need to do
+ * aggregation so that count(*) shows 0, rather than NULL.
+ */
+ if (winstate->rpSkipTo == ST_PAST_LAST_ROW &&
+ get_reduced_frame_map(winstate, winstate->currentpos) == RF_SKIPPED)
+ agg_result_isnull = true;
}
/*
@@ -930,6 +1032,11 @@ eval_windowaggregates(WindowAggState *winstate)
{
int ret;
+ elog(DEBUG1, "===== loop in frame starts: " INT64_FORMAT, winstate->aggregatedupto);
+
+ if (agg_result_isnull)
+ break;
+
/* Fetch next row if we didn't already */
if (TupIsNull(agg_row_slot))
{
@@ -945,9 +1052,28 @@ eval_windowaggregates(WindowAggState *winstate)
ret = row_is_in_frame(winstate, winstate->aggregatedupto, agg_row_slot);
if (ret < 0)
break;
+
if (ret == 0)
goto next_tuple;
+ if (rpr_is_defined(winstate))
+ {
+ /*
+ * If the row status at currentpos is already decided and current
+ * row status is not decided yet, it means we passed the last
+ * reduced frame. Time to break the loop.
+ */
+ if (get_reduced_frame_map(winstate, winstate->currentpos) != RF_NOT_DETERMINED &&
+ get_reduced_frame_map(winstate, winstate->aggregatedupto) == RF_NOT_DETERMINED)
+ break;
+ /*
+ * Otherwise we need to calculate the reduced frame.
+ */
+ ret = row_is_in_reduced_frame(winstate->agg_winobj, winstate->aggregatedupto);
+ if (ret == -1) /* unmatched row */
+ break;
+ }
+
/* Set tuple context for evaluation of aggregate arguments */
winstate->tmpcontext->ecxt_outertuple = agg_row_slot;
@@ -976,6 +1102,7 @@ next_tuple:
ExecClearTuple(agg_row_slot);
}
+
/* The frame's end is not supposed to move backwards, ever */
Assert(aggregatedupto_nonrestarted <= winstate->aggregatedupto);
@@ -996,6 +1123,16 @@ next_tuple:
peraggstate,
result, isnull);
+ /*
+ * RPR is defined and we just return NULL because skip mode is SKIP
+ * TO PAST LAST ROW and current row is skipped row.
+ */
+ if (agg_result_isnull)
+ {
+ *isnull = true;
+ *result = (Datum) 0;
+ }
+
/*
* save the result in case next row shares the same frame.
*
@@ -1090,6 +1227,7 @@ begin_partition(WindowAggState *winstate)
winstate->framehead_valid = false;
winstate->frametail_valid = false;
winstate->grouptail_valid = false;
+ create_reduced_frame_map(winstate);
winstate->spooled_rows = 0;
winstate->currentpos = 0;
winstate->frameheadpos = 0;
@@ -2053,6 +2191,8 @@ ExecWindowAgg(PlanState *pstate)
CHECK_FOR_INTERRUPTS();
+ elog(DEBUG1, "ExecWindowAgg called. pos: " INT64_FORMAT , winstate->currentpos);
+
if (winstate->status == WINDOWAGG_DONE)
return NULL;
@@ -2221,6 +2361,17 @@ ExecWindowAgg(PlanState *pstate)
/* don't evaluate the window functions when we're in pass-through mode */
if (winstate->status == WINDOWAGG_RUN)
{
+ /*
+ * If RPR is defined and skip mode is next row, we need to clear existing
+ * reduced frame info so that we newly calculate the info starting from
+ * current row.
+ */
+ if (rpr_is_defined(winstate))
+ {
+ if (winstate->rpSkipTo == ST_NEXT_ROW)
+ clear_reduced_frame_map(winstate);
+ }
+
/*
* Evaluate true window functions
*/
@@ -2388,6 +2539,9 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
TupleDesc scanDesc;
ListCell *l;
+ TargetEntry *te;
+ Expr *expr;
+
/* check for unsupported flags */
Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
@@ -2483,6 +2637,16 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
winstate->temp_slot_2 = ExecInitExtraTupleSlot(estate, scanDesc,
&TTSOpsMinimalTuple);
+ winstate->prev_slot = ExecInitExtraTupleSlot(estate, scanDesc,
+ &TTSOpsMinimalTuple);
+
+ winstate->next_slot = ExecInitExtraTupleSlot(estate, scanDesc,
+ &TTSOpsMinimalTuple);
+
+ winstate->null_slot = ExecInitExtraTupleSlot(estate, scanDesc,
+ &TTSOpsMinimalTuple);
+ winstate->null_slot = ExecStoreAllNullTuple(winstate->null_slot);
+
/*
* create frame head and tail slots only if needed (must create slots in
* exactly the same cases that update_frameheadpos and update_frametailpos
@@ -2667,6 +2831,39 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
winstate->inRangeAsc = node->inRangeAsc;
winstate->inRangeNullsFirst = node->inRangeNullsFirst;
+ /* Set up SKIP TO type */
+ winstate->rpSkipTo = node->rpSkipTo;
+ /* Set up row pattern recognition PATTERN clause */
+ winstate->patternVariableList = node->patternVariable;
+ winstate->patternRegexpList = node->patternRegexp;
+
+ /* Set up row pattern recognition DEFINE clause */
+ winstate->defineInitial = node->defineInitial;
+ winstate->defineVariableList = NIL;
+ winstate->defineClauseList = NIL;
+ if (node->defineClause != NIL)
+ {
+ /*
+ * Tweak arg var of PREV/NEXT so that it refers to scan/inner slot.
+ */
+ foreach(l, node->defineClause)
+ {
+ char *name;
+ ExprState *exps;
+
+ te = lfirst(l);
+ name = te->resname;
+ expr = te->expr;
+
+ elog(DEBUG1, "defineVariable name: %s", name);
+ winstate->defineVariableList = lappend(winstate->defineVariableList,
+ makeString(pstrdup(name)));
+ attno_map((Node *)expr);
+ exps = ExecInitExpr(expr, (PlanState *) winstate);
+ winstate->defineClauseList = lappend(winstate->defineClauseList, exps);
+ }
+ }
+
winstate->all_first = true;
winstate->partition_spooled = false;
winstate->more_partitions = false;
@@ -2674,6 +2871,57 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
return winstate;
}
+/*
+ * Rewrite varno of Var node that is the argument of PREV/NET so that it sees
+ * scan tuple (PREV) or inner tuple (NEXT).
+ */
+static void
+attno_map(Node *node)
+{
+ (void) expression_tree_walker(node, attno_map_walker, NULL);
+}
+
+static bool
+attno_map_walker(Node *node, void *context)
+{
+ FuncExpr *func;
+ int nargs;
+ Expr *expr;
+ Var *var;
+
+ if (node == NULL)
+ return false;
+
+ if (IsA(node, FuncExpr))
+ {
+ func = (FuncExpr *)node;
+
+ if (func->funcid == F_PREV || func->funcid == F_NEXT)
+ {
+ /* sanity check */
+ nargs = list_length(func->args);
+ if (list_length(func->args) != 1)
+ elog(ERROR, "PREV/NEXT must have 1 argument but function %d has %d args", func->funcid, nargs);
+
+ expr = (Expr *) lfirst(list_head(func->args));
+ if (!IsA(expr, Var))
+ elog(ERROR, "PREV/NEXT's arg is not Var"); /* XXX: is it possible that arg type is Const? */
+ var = (Var *)expr;
+
+ if (func->funcid == F_PREV)
+ /*
+ * Rewrite varno from OUTER_VAR to regular var no so that the
+ * var references scan tuple.
+ */
+ var->varno = var->varnosyn;
+ else
+ var->varno = INNER_VAR;
+ elog(DEBUG1, "PREV/NEXT's varno is rewritten to: %d", var->varno);
+ }
+ }
+ return expression_tree_walker(node, attno_map_walker, NULL);
+}
+
/* -----------------
* ExecEndWindowAgg
* -----------------
@@ -2723,6 +2971,8 @@ ExecReScanWindowAgg(WindowAggState *node)
ExecClearTuple(node->agg_row_slot);
ExecClearTuple(node->temp_slot_1);
ExecClearTuple(node->temp_slot_2);
+ ExecClearTuple(node->prev_slot);
+ ExecClearTuple(node->next_slot);
if (node->framehead_slot)
ExecClearTuple(node->framehead_slot);
if (node->frametail_slot)
@@ -3083,7 +3333,7 @@ window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot)
return false;
if (pos < winobj->markpos)
- elog(ERROR, "cannot fetch row before WindowObject's mark position");
+ elog(ERROR, "cannot fetch row: " INT64_FORMAT " before WindowObject's mark position: " INT64_FORMAT, pos, winobj->markpos );
oldcontext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory);
@@ -3403,14 +3653,54 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno,
WindowAggState *winstate;
ExprContext *econtext;
TupleTableSlot *slot;
- int64 abs_pos;
- int64 mark_pos;
Assert(WindowObjectIsValid(winobj));
winstate = winobj->winstate;
econtext = winstate->ss.ps.ps_ExprContext;
slot = winstate->temp_slot_1;
+ if (WinGetSlotInFrame(winobj, slot,
+ relpos, seektype, set_mark,
+ isnull, isout) == 0)
+ {
+ econtext->ecxt_outertuple = slot;
+ return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
+ econtext, isnull);
+ }
+
+ if (isout)
+ *isout = true;
+ *isnull = true;
+ return (Datum) 0;
+}
+
+/*
+ * WinGetSlotInFrame
+ * slot: TupleTableSlot to store the result
+ * relpos: signed rowcount offset from the seek position
+ * seektype: WINDOW_SEEK_HEAD or WINDOW_SEEK_TAIL
+ * set_mark: If the row is found/in frame and set_mark is true, the mark is
+ * moved to the row as a side-effect.
+ * isnull: output argument, receives isnull status of result
+ * isout: output argument, set to indicate whether target row position
+ * is out of frame (can pass NULL if caller doesn't care about this)
+ *
+ * Returns 0 if we successfullt got the slot. false if out of frame.
+ * (also isout is set)
+ */
+static int
+WinGetSlotInFrame(WindowObject winobj, TupleTableSlot *slot,
+ int relpos, int seektype, bool set_mark,
+ bool *isnull, bool *isout)
+{
+ WindowAggState *winstate;
+ int64 abs_pos;
+ int64 mark_pos;
+ int num_reduced_frame;
+
+ Assert(WindowObjectIsValid(winobj));
+ winstate = winobj->winstate;
+
switch (seektype)
{
case WINDOW_SEEK_CURRENT:
@@ -3477,11 +3767,21 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno,
winstate->frameOptions);
break;
}
+ num_reduced_frame = row_is_in_reduced_frame(winobj, winstate->frameheadpos);
+ if (num_reduced_frame < 0)
+ goto out_of_frame;
+ else if (num_reduced_frame > 0)
+ if (relpos >= num_reduced_frame)
+ goto out_of_frame;
break;
case WINDOW_SEEK_TAIL:
/* rejecting relpos > 0 is easy and simplifies code below */
if (relpos > 0)
goto out_of_frame;
+
+ /* RPR cares about frame head pos. Need to call update_frameheadpos */
+ update_frameheadpos(winstate);
+
update_frametailpos(winstate);
abs_pos = winstate->frametailpos - 1 + relpos;
@@ -3548,6 +3848,12 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno,
mark_pos = 0; /* keep compiler quiet */
break;
}
+
+ num_reduced_frame = row_is_in_reduced_frame(winobj, winstate->frameheadpos + relpos);
+ if (num_reduced_frame < 0)
+ goto out_of_frame;
+ else if (num_reduced_frame > 0)
+ abs_pos = winstate->frameheadpos + relpos + num_reduced_frame - 1;
break;
default:
elog(ERROR, "unrecognized window seek type: %d", seektype);
@@ -3566,15 +3872,13 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno,
*isout = false;
if (set_mark)
WinSetMarkPosition(winobj, mark_pos);
- econtext->ecxt_outertuple = slot;
- return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
- econtext, isnull);
+ return 0;
out_of_frame:
if (isout)
*isout = true;
*isnull = true;
- return (Datum) 0;
+ return -1;
}
/*
@@ -3605,3 +3909,1097 @@ WinGetFuncArgCurrent(WindowObject winobj, int argno, bool *isnull)
return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
econtext, isnull);
}
+
+/*
+ * rpr_is_defined
+ * return true if Row pattern recognition is defined.
+ */
+static
+bool rpr_is_defined(WindowAggState *winstate)
+{
+ return winstate->patternVariableList != NIL;
+}
+
+/*
+ * row_is_in_reduced_frame
+ * Determine whether a row is in the current row's reduced window frame according
+ * to row pattern matching
+ *
+ * The row must has been already determined that it is in a full window frame
+ * and fetched it into slot.
+ *
+ * Returns:
+ * = 0, RPR is not defined.
+ * >0, if the row is the first in the reduced frame. Return the number of rows in the reduced frame.
+ * -1, if the row is unmatched row
+ * -2, if the row is in the reduced frame but needed to be skipped because of
+ * AFTER MATCH SKIP PAST LAST ROW
+ */
+static
+int row_is_in_reduced_frame(WindowObject winobj, int64 pos)
+{
+ WindowAggState *winstate = winobj->winstate;
+ int state;
+ int rtn;
+
+ if (!rpr_is_defined(winstate))
+ {
+ /*
+ * RPR is not defined. Assume that we are always in the the reduced
+ * window frame.
+ */
+ rtn = 0;
+ elog(DEBUG1, "row_is_in_reduced_frame returns %d: pos: " INT64_FORMAT, rtn, pos);
+ return rtn;
+ }
+
+ state = get_reduced_frame_map(winstate, pos);
+
+ if (state == RF_NOT_DETERMINED)
+ {
+ update_frameheadpos(winstate);
+ update_reduced_frame(winobj, pos);
+ }
+
+ state = get_reduced_frame_map(winstate, pos);
+
+ switch (state)
+ {
+ int64 i;
+ int num_reduced_rows;
+
+ case RF_FRAME_HEAD:
+ num_reduced_rows = 1;
+ for (i = pos + 1; get_reduced_frame_map(winstate,i) == RF_SKIPPED; i++)
+ num_reduced_rows++;
+ rtn = num_reduced_rows;
+ break;
+
+ case RF_SKIPPED:
+ rtn = -2;
+ break;
+
+ case RF_UNMATCHED:
+ rtn = -1;
+ break;
+
+ default:
+ elog(ERROR, "Unrecognized state: %d at: " INT64_FORMAT, state, pos);
+ break;
+ }
+
+ elog(DEBUG1, "row_is_in_reduced_frame returns %d: pos: " INT64_FORMAT, rtn, pos);
+ return rtn;
+}
+
+#define REDUCED_FRAME_MAP_INIT_SIZE 1024L
+
+/*
+ * Create reduced frame map
+ */
+static
+void create_reduced_frame_map(WindowAggState *winstate)
+{
+ winstate->reduced_frame_map =
+ MemoryContextAlloc(winstate->partcontext, REDUCED_FRAME_MAP_INIT_SIZE);
+ winstate->alloc_sz = REDUCED_FRAME_MAP_INIT_SIZE;
+ clear_reduced_frame_map(winstate);
+}
+
+/*
+ * Clear reduced frame map
+ */
+static
+void clear_reduced_frame_map(WindowAggState *winstate)
+{
+ Assert(winstate->reduced_frame_map != NULL);
+ MemSet(winstate->reduced_frame_map, RF_NOT_DETERMINED,
+ winstate->alloc_sz);
+}
+
+/*
+ * Get reduced frame map specified by pos
+ */
+static
+int get_reduced_frame_map(WindowAggState *winstate, int64 pos)
+{
+ Assert(winstate->reduced_frame_map != NULL);
+
+ if (pos < 0 || pos >= winstate->alloc_sz)
+ elog(ERROR, "wrong pos: " INT64_FORMAT, pos);
+
+ return winstate->reduced_frame_map[pos];
+}
+
+/*
+ * Add/replace reduced frame map member at pos.
+ * If there's no enough space, expand the map.
+ */
+static
+void register_reduced_frame_map(WindowAggState *winstate, int64 pos, int val)
+{
+ int64 realloc_sz;
+
+ Assert(winstate->reduced_frame_map != NULL);
+
+ if (pos < 0)
+ elog(ERROR, "wrong pos: " INT64_FORMAT, pos);
+
+ if (pos > winstate->alloc_sz - 1)
+ {
+ realloc_sz = winstate->alloc_sz * 2;
+
+ winstate->reduced_frame_map =
+ repalloc(winstate->reduced_frame_map, realloc_sz);
+
+ MemSet(winstate->reduced_frame_map + winstate->alloc_sz,
+ RF_NOT_DETERMINED, realloc_sz - winstate->alloc_sz);
+
+ winstate->alloc_sz = realloc_sz;
+ }
+
+ winstate->reduced_frame_map[pos] = val;
+}
+
+/*
+ * update_reduced_frame
+ * Update reduced frame info.
+ */
+static
+void update_reduced_frame(WindowObject winobj, int64 pos)
+{
+ WindowAggState *winstate = winobj->winstate;
+ ListCell *lc1, *lc2;
+ bool expression_result;
+ int num_matched_rows;
+ int64 original_pos;
+ bool anymatch;
+ StringInfo encoded_str;
+ StringInfo pattern_str = makeStringInfo();
+ StringSet *str_set;
+ int str_set_index = 0;
+ int initial_index;
+ VariablePos *variable_pos;
+ bool greedy = false;
+ int64 result_pos, i;
+
+ /*
+ * Set of pattern variables evaluated to true.
+ * Each character corresponds to pattern variable.
+ * Example:
+ * str_set[0] = "AB";
+ * str_set[1] = "AC";
+ * In this case at row 0 A and B are true, and A and C are true in row 1.
+ */
+
+ /* initialize pattern variables set */
+ str_set = string_set_init();
+
+ /* save original pos */
+ original_pos = pos;
+
+ /*
+ * Check if the pattern does not include any greedy quantifier.
+ * If it does not, we can just apply the pattern to each row.
+ * If it succeeds, we are done.
+ */
+ foreach(lc1, winstate->patternRegexpList)
+ {
+ char *quantifier = strVal(lfirst(lc1));
+ if (*quantifier == '+' || *quantifier == '*')
+ {
+ greedy = true;
+ break;
+ }
+ }
+ if (!greedy)
+ {
+ num_matched_rows = 0;
+
+ foreach(lc1, winstate->patternVariableList)
+ {
+ char *vname = strVal(lfirst(lc1));
+
+ encoded_str = makeStringInfo();
+
+ elog(DEBUG1, "pos: " INT64_FORMAT " pattern vname: %s", pos, vname);
+
+ expression_result = false;
+
+ /* evaluate row pattern against current row */
+ result_pos = evaluate_pattern(winobj, pos, vname, encoded_str, &expression_result);
+ if (!expression_result || result_pos < 0)
+ {
+ elog(DEBUG1, "expression result is false or out of frame");
+ register_reduced_frame_map(winstate, original_pos, RF_UNMATCHED);
+ return;
+ }
+ /* move to next row */
+ pos++;
+ num_matched_rows++;
+ }
+ elog(DEBUG1, "pattern matched");
+
+ register_reduced_frame_map(winstate, original_pos, RF_FRAME_HEAD);
+
+ for (i = original_pos + 1; i < original_pos + num_matched_rows; i++)
+ {
+ register_reduced_frame_map(winstate, i, RF_SKIPPED);
+ }
+ return;
+ }
+
+ /*
+ * Greedy quantifiers included.
+ * Loop over until none of pattern matches or encounters end of frame.
+ */
+ for (;;)
+ {
+ result_pos = -1;
+
+ /*
+ * Loop over each PATTERN variable.
+ */
+ anymatch = false;
+ encoded_str = makeStringInfo();
+
+ forboth(lc1, winstate->patternVariableList, lc2, winstate->patternRegexpList)
+ {
+ char *vname = strVal(lfirst(lc1));
+ char *quantifier = strVal(lfirst(lc2));
+
+ elog(DEBUG1, "pos: " INT64_FORMAT " pattern vname: %s quantifier: %s", pos, vname, quantifier);
+
+ expression_result = false;
+
+ /* evaluate row pattern against current row */
+ result_pos = evaluate_pattern(winobj, pos, vname, encoded_str, &expression_result);
+ if (expression_result)
+ {
+ elog(DEBUG1, "expression result is true");
+ anymatch = true;
+ }
+
+ /*
+ * If out of frame, we are done.
+ */
+ if (result_pos < 0)
+ break;
+ }
+
+ if (!anymatch)
+ {
+ /* none of patterns matched. */
+ break;
+ }
+
+ string_set_add(str_set, encoded_str);
+
+ elog(DEBUG1, "pos: " INT64_FORMAT " str_set_index: %d encoded_str: %s", pos, str_set_index, encoded_str->data);
+
+ /* move to next row */
+ pos++;
+
+ if (result_pos < 0)
+ {
+ /* out of frame */
+ break;
+ }
+ }
+
+ if (string_set_get_size(str_set) == 0)
+ {
+ /* no match found in the first row */
+ register_reduced_frame_map(winstate, original_pos, RF_UNMATCHED);
+ return;
+ }
+
+ elog(DEBUG2, "pos: " INT64_FORMAT " encoded_str: %s", pos, encoded_str->data);
+
+ /* build regular expression */
+ pattern_str = makeStringInfo();
+ appendStringInfoChar(pattern_str, '^');
+ initial_index = 0;
+
+ variable_pos = variable_pos_init();
+
+ forboth (lc1, winstate->patternVariableList, lc2, winstate->patternRegexpList)
+ {
+ char *vname = strVal(lfirst(lc1));
+ char *quantifier = strVal(lfirst(lc2));
+ char initial;
+
+ initial = pattern_initial(winstate, vname);
+ Assert(initial != 0);
+ appendStringInfoChar(pattern_str, initial);
+ if (quantifier[0])
+ appendStringInfoChar(pattern_str, quantifier[0]);
+
+ /*
+ * Register the initial at initial_index. If the initial appears more
+ * than once, all of it's initial_index will be recorded. This could
+ * happen if a pattern variable appears in the PATTERN clause more
+ * than once like "UP DOWN UP" "UP UP UP".
+ */
+ variable_pos_register(variable_pos, initial, initial_index);
+
+ initial_index++;
+ }
+
+ elog(DEBUG2, "pos: " INT64_FORMAT " pattern: %s", pos, pattern_str->data);
+
+ /* look for matching pattern variable sequence */
+ elog(DEBUG1, "search_str_set started");
+ num_matched_rows = search_str_set(pattern_str->data, str_set, variable_pos);
+ elog(DEBUG1, "search_str_set returns: %d", num_matched_rows);
+
+ variable_pos_discard(variable_pos);
+ string_set_discard(str_set);
+
+ /*
+ * We are at the first row in the reduced frame. Save the number of
+ * matched rows as the number of rows in the reduced frame.
+ */
+ if (num_matched_rows <= 0)
+ {
+ /* no match */
+ register_reduced_frame_map(winstate, original_pos, RF_UNMATCHED);
+ }
+ else
+ {
+ register_reduced_frame_map(winstate, original_pos, RF_FRAME_HEAD);
+
+ for (i = original_pos + 1; i < original_pos + num_matched_rows; i++)
+ {
+ register_reduced_frame_map(winstate, i, RF_SKIPPED);
+ }
+ }
+
+ return;
+}
+
+/*
+ * Perform pattern matching using pattern against str_set. pattern is a
+ * regular expression derived from PATTERN clause. Note that the regular
+ * expression string is prefixed by '^' and followed by initials represented
+ * in a same way as str_set. str_set is a set of StringInfo. Each StringInfo
+ * has a string comprising initials of pattern variable strings being true in
+ * a row. The initials are one of [a-y], parallel to the order of variable
+ * names in DEFINE clause. For example, if DEFINE has variables START, UP and
+ * DOWN, PATTERN HAS START, UP and DOWN, then the initials in PATTERN will be
+ * 'a', 'b' and 'c'.
+ *
+ * variable_pos is an array representing the order of pattern variable string
+ * initials in PATTERN clause. For example initial 'a' potion is in
+ * variable_pos[0].pos[0] = 0. Note that if the pattern is "START UP DOWN UP"
+ * (UP appears twice), then "UP" (initial is 'b') has two position 1 and
+ * 3. Thus variable_pos for b is variable_pos[1].pos[0] = 1 and
+ * variable_pos[1].pos[1] = 3.
+ *
+ * Returns the longest number of the matching rows.
+ */
+static
+int search_str_set(char *pattern, StringSet *str_set, VariablePos *variable_pos)
+{
+#define MAX_CANDIDATE_NUM 10000 /* max pattern match candidate size */
+#define FREEZED_CHAR 'Z' /* a pattern is freezed if it ends with the char */
+#define DISCARD_CHAR 'z' /* a pattern is not need to keep */
+
+ int set_size; /* number of rows in the set */
+ int resultlen;
+ int index;
+ StringSet *old_str_set, *new_str_set;
+ int new_str_size;
+ int len;
+
+ set_size = string_set_get_size(str_set);
+ new_str_set = string_set_init();
+ len = 0;
+ resultlen = 0;
+
+ /*
+ * Generate all possible pattern variable name initials as a set of
+ * StringInfo named "new_str_set". For example, if we have two rows
+ * having "ab" (row 0) and "ac" (row 1) in the input str_set, new_str_set
+ * will have set of StringInfo "aa", "ac", "ba" and "bc" in the end.
+ */
+ elog(DEBUG1, "pattern: %s set_size: %d", pattern, set_size);
+ for (index = 0; index < set_size; index++)
+ {
+ StringInfo str; /* search target row */
+ char *p;
+ int old_set_size;
+ int i;
+
+ elog(DEBUG1, "index: %d", index);
+
+ if (index == 0)
+ {
+ /* copy variables in row 0 */
+ str = string_set_get(str_set, index);
+ p = str->data;
+
+ /*
+ * Loop over each new pattern variable char.
+ */
+ while (*p)
+ {
+ StringInfo new = makeStringInfo();
+
+ /* add pattern variable char */
+ appendStringInfoChar(new, *p);
+ /* add new one to string set */
+ string_set_add(new_str_set, new);
+ elog(DEBUG1, "old_str: NULL new_str: %s", new->data);
+ p++; /* next pattern variable */
+ }
+ }
+ else /* index != 0 */
+ {
+ old_str_set = new_str_set;
+ new_str_set = string_set_init();
+ str = string_set_get(str_set, index);
+ old_set_size = string_set_get_size(old_str_set);
+
+ /*
+ * Loop over each rows in the previous result set.
+ */
+ for (i = 0; i < old_set_size ; i++)
+ {
+ StringInfo new;
+ char last_old_char;
+ int old_str_len;
+ StringInfo old = string_set_get(old_str_set, i);
+
+ p = old->data;
+ old_str_len = strlen(p);
+ if (old_str_len > 0)
+ last_old_char = p[old_str_len - 1];
+ else
+ last_old_char = '\0';
+
+ /* Is this old set freezed? */
+ if (last_old_char == FREEZED_CHAR)
+ {
+ /* if shorter match. we can discard it */
+ if ((old_str_len - 1) < resultlen)
+ {
+ elog(DEBUG1, "discard this old set because shorter match: %s", old->data);
+ continue;
+ }
+
+ elog(DEBUG1, "keep this old set: %s", old->data);
+
+ /* move the old set to new_str_set */
+ string_set_add(new_str_set, old);
+ old_str_set->str_set[i] = NULL;
+ continue;
+ }
+ /* Can this old set be discarded? */
+ else if (last_old_char == DISCARD_CHAR)
+ {
+ elog(DEBUG1, "discard this old set: %s", old->data);
+ continue;
+ }
+
+ elog(DEBUG1, "str->data: %s", str->data);
+
+ /*
+ * loop over each pattern variable initial char in the input
+ * set.
+ */
+ for (p = str->data; *p; p++)
+ {
+ /*
+ * Optimization. Check if the row's pattern variable
+ * initial character position is greater than or equal to
+ * the old set's last pattern variable initial character
+ * position. For example, if the old set's last pattern
+ * variable initials are "ab", then the new pattern
+ * variable initial can be "b" or "c" but can not be "a",
+ * if the initials in PATTERN is something like "a b c" or
+ * "a b+ c+" etc. This optimization is possible when we
+ * only allow "+" quantifier.
+ */
+ if (variable_pos_compare(variable_pos, last_old_char, *p))
+ {
+ /* copy source string */
+ new = makeStringInfo();
+ enlargeStringInfo(new, old->len + 1);
+ appendStringInfoString(new, old->data);
+ /* add pattern variable char */
+ appendStringInfoChar(new, *p);
+ elog(DEBUG1, "old_str: %s new_str: %s", old->data, new->data);
+
+ /*
+ * Adhoc optimization. If the first letter in the
+ * input string is the first and second position one
+ * and there's no associated quatifier '+', then we
+ * can dicard the input because there's no chace to
+ * expand the string further.
+ *
+ * For example, pattern "abc" cannot match "aa".
+ */
+ elog(DEBUG1, "pattern[1]:%c pattern[2]:%c new[0]:%c new[1]:%c",
+ pattern[1], pattern[2], new->data[0], new->data[1]);
+ if (pattern[1] == new->data[0] &&
+ pattern[1] == new->data[1] &&
+ pattern[2] != '+' &&
+ pattern[1] != pattern[2])
+ {
+ elog(DEBUG1, "discard this new data: %s",
+ new->data);
+ pfree(new->data);
+ pfree(new);
+ continue;
+ }
+
+ /* add new one to string set */
+ string_set_add(new_str_set, new);
+ }
+ else
+ {
+ /*
+ * We are freezing this pattern string. Since there's
+ * no chance to expand the string further, we perform
+ * pattern matching against the string. If it does not
+ * match, we can discard it.
+ */
+ len = do_pattern_match(pattern, old->data);
+
+ if (len <= 0)
+ {
+ /* no match. we can discard it */
+ continue;
+ }
+
+ else if (len <= resultlen)
+ {
+ /* shorter match. we can discard it */
+ continue;
+ }
+ else
+ {
+ /* match length is the longest so far */
+
+ int new_index;
+
+ /* remember the longest match */
+ resultlen = len;
+
+ /* freeze the pattern string */
+ new = makeStringInfo();
+ enlargeStringInfo(new, old->len + 1);
+ appendStringInfoString(new, old->data);
+ /* add freezed mark */
+ appendStringInfoChar(new, FREEZED_CHAR);
+ elog(DEBUG1, "old_str: %s new_str: %s", old->data, new->data);
+ string_set_add(new_str_set, new);
+
+ /*
+ * Search new_str_set to find out freezed
+ * entries that have shorter match length.
+ * Mark them as "discard" so that they are
+ * discarded in the next round.
+ */
+
+ /* new_index_size should be the one before */
+ new_str_size = string_set_get_size(new_str_set) - 1;
+
+ /* loop over new_str_set */
+ for (new_index = 0; new_index < new_str_size; new_index++)
+ {
+ char new_last_char;
+ int new_str_len;
+
+ new = string_set_get(new_str_set, new_index);
+ new_str_len = strlen(new->data);
+ if (new_str_len > 0)
+ {
+ new_last_char = new->data[new_str_len - 1];
+ if (new_last_char == FREEZED_CHAR &&
+ (new_str_len - 1) <= len)
+ {
+ /* mark this set to discard in the next round */
+ appendStringInfoChar(new, DISCARD_CHAR);
+ elog(DEBUG1, "add discard char: %s", new->data);
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ /* we no longer need old string set */
+ string_set_discard(old_str_set);
+ }
+ }
+
+ /*
+ * Perform pattern matching to find out the longest match.
+ */
+ new_str_size = string_set_get_size(new_str_set);
+ elog(DEBUG1, "new_str_size: %d", new_str_size);
+ len = 0;
+ resultlen = 0;
+
+ for (index = 0; index < new_str_size; index++)
+ {
+ StringInfo s;
+
+ s = string_set_get(new_str_set, index);
+ if (s == NULL)
+ continue; /* no data */
+
+ elog(DEBUG1, "target string: %s", s->data);
+
+ len = do_pattern_match(pattern, s->data);
+ if (len > resultlen)
+ {
+ /* remember the longest match */
+ resultlen = len;
+
+ /*
+ * If the size of result set is equal to the number of rows in the
+ * set, we are done because it's not possible that the number of
+ * matching rows exceeds the number of rows in the set.
+ */
+ if (resultlen >= set_size)
+ break;
+ }
+ }
+
+ /* we no longer need new string set */
+ string_set_discard(new_str_set);
+
+ return resultlen;
+}
+
+/*
+ * do_pattern_match
+ * perform pattern match using pattern against encoded_str.
+ * returns matching number of rows if matching is succeeded.
+ * Otherwise returns 0.
+ */
+static
+int do_pattern_match(char *pattern, char *encoded_str)
+{
+ Datum d;
+ text *res;
+ char *substr;
+ int len = 0;
+ text *pattern_text, *encoded_str_text;
+
+ pattern_text = cstring_to_text(pattern);
+ encoded_str_text = cstring_to_text(encoded_str);
+
+ /*
+ * We first perform pattern matching using regexp_instr, then call
+ * textregexsubstr to get matched substring to know how long the
+ * matched string is. That is the number of rows in the reduced window
+ * frame. The reason why we can't call textregexsubstr in the first
+ * place is, it errors out if pattern does not match.
+ */
+ if (DatumGetInt32(DirectFunctionCall2Coll(regexp_instr, DEFAULT_COLLATION_OID,
+ PointerGetDatum(encoded_str_text),
+ PointerGetDatum(pattern_text))))
+ {
+ d = DirectFunctionCall2Coll(textregexsubstr,
+ DEFAULT_COLLATION_OID,
+ PointerGetDatum(encoded_str_text),
+ PointerGetDatum(pattern_text));
+ if (d != 0)
+ {
+ res = DatumGetTextPP(d);
+ substr = text_to_cstring(res);
+ len = strlen(substr);
+ pfree(substr);
+ }
+ }
+ pfree(encoded_str_text);
+ pfree(pattern_text);
+
+ return len;
+}
+
+
+/*
+ * Evaluate expression associated with PATTERN variable vname.
+ * relpos is relative row position in a frame (starting from 0).
+ * "quantifier" is the quatifier part of the PATTERN regular expression.
+ * Currently only '+' is allowed.
+ * result is out paramater representing the expression evaluation result
+ * is true of false.
+ * Return values are:
+ * >=0: the last match absolute row position
+ * other wise out of frame.
+ */
+static
+int64 evaluate_pattern(WindowObject winobj, int64 current_pos,
+ char *vname, StringInfo encoded_str, bool *result)
+{
+ WindowAggState *winstate = winobj->winstate;
+ ExprContext *econtext = winstate->ss.ps.ps_ExprContext;
+ ListCell *lc1, *lc2, *lc3;
+ ExprState *pat;
+ Datum eval_result;
+ bool out_of_frame = false;
+ bool isnull;
+ TupleTableSlot *slot;
+
+ forthree (lc1, winstate->defineVariableList, lc2, winstate->defineClauseList, lc3, winstate->defineInitial)
+ {
+ char initial;
+ char *name = strVal(lfirst(lc1));
+
+ if (strcmp(vname, name))
+ continue;
+
+ initial = *(strVal(lfirst(lc3)));
+
+ /* set expression to evaluate */
+ pat = lfirst(lc2);
+
+ /* get current, previous and next tuples */
+ if (!get_slots(winobj, current_pos))
+ {
+ out_of_frame = true;
+ }
+ else
+ {
+ /* evaluate the expression */
+ eval_result = ExecEvalExpr(pat, econtext, &isnull);
+ if (isnull)
+ {
+ /* expression is NULL */
+ elog(DEBUG1, "expression for %s is NULL at row: " INT64_FORMAT, vname, current_pos);
+ *result = false;
+ }
+ else
+ {
+ if (!DatumGetBool(eval_result))
+ {
+ /* expression is false */
+ elog(DEBUG1, "expression for %s is false at row: " INT64_FORMAT, vname, current_pos);
+ *result = false;
+ }
+ else
+ {
+ /* expression is true */
+ elog(DEBUG1, "expression for %s is true at row: " INT64_FORMAT, vname, current_pos);
+ appendStringInfoChar(encoded_str, initial);
+ *result = true;
+ }
+ }
+
+ slot = winstate->temp_slot_1;
+ if (slot != winstate->null_slot)
+ ExecClearTuple(slot);
+ slot = winstate->prev_slot;
+ if (slot != winstate->null_slot)
+ ExecClearTuple(slot);
+ slot = winstate->next_slot;
+ if (slot != winstate->null_slot)
+ ExecClearTuple(slot);
+
+ break;
+ }
+
+ if (out_of_frame)
+ {
+ *result = false;
+ return -1;
+ }
+ }
+ return current_pos;
+}
+
+/*
+ * Get current, previous and next tuples.
+ * Returns false if current row is out of partition/full frame.
+ */
+static
+bool get_slots(WindowObject winobj, int64 current_pos)
+{
+ WindowAggState *winstate = winobj->winstate;
+ TupleTableSlot *slot;
+ int ret;
+ ExprContext *econtext;
+
+ econtext = winstate->ss.ps.ps_ExprContext;
+
+ /* set up current row tuple slot */
+ slot = winstate->temp_slot_1;
+ if (!window_gettupleslot(winobj, current_pos, slot))
+ {
+ elog(DEBUG1, "current row is out of partition at:" INT64_FORMAT, current_pos);
+ return false;
+ }
+ ret = row_is_in_frame(winstate, current_pos, slot);
+ if (ret <= 0)
+ {
+ elog(DEBUG1, "current row is out of frame at: " INT64_FORMAT, current_pos);
+ ExecClearTuple(slot);
+ return false;
+ }
+ econtext->ecxt_outertuple = slot;
+
+ /* for PREV */
+ if (current_pos > 0)
+ {
+ slot = winstate->prev_slot;
+ if (!window_gettupleslot(winobj, current_pos - 1, slot))
+ {
+ elog(DEBUG1, "previous row is out of partition at: " INT64_FORMAT, current_pos - 1);
+ econtext->ecxt_scantuple = winstate->null_slot;
+ }
+ else
+ {
+ ret = row_is_in_frame(winstate, current_pos - 1, slot);
+ if (ret <= 0)
+ {
+ elog(DEBUG1, "previous row is out of frame at: " INT64_FORMAT, current_pos - 1);
+ ExecClearTuple(slot);
+ econtext->ecxt_scantuple = winstate->null_slot;
+ }
+ else
+ {
+ econtext->ecxt_scantuple = slot;
+ }
+ }
+ }
+ else
+ econtext->ecxt_scantuple = winstate->null_slot;
+
+ /* for NEXT */
+ slot = winstate->next_slot;
+ if (!window_gettupleslot(winobj, current_pos + 1, slot))
+ {
+ elog(DEBUG1, "next row is out of partiton at: " INT64_FORMAT, current_pos + 1);
+ econtext->ecxt_innertuple = winstate->null_slot;
+ }
+ else
+ {
+ ret = row_is_in_frame(winstate, current_pos + 1, slot);
+ if (ret <= 0)
+ {
+ elog(DEBUG1, "next row is out of frame at: " INT64_FORMAT, current_pos + 1);
+ ExecClearTuple(slot);
+ econtext->ecxt_innertuple = winstate->null_slot;
+ }
+ else
+ econtext->ecxt_innertuple = slot;
+ }
+ return true;
+}
+
+/*
+ * Return pattern variable initial character
+ * matching with pattern variable name vname.
+ * If not found, return 0.
+ */
+static
+char pattern_initial(WindowAggState *winstate, char *vname)
+{
+ char initial;
+ char *name;
+ ListCell *lc1, *lc2;
+
+ forboth (lc1, winstate->defineVariableList, lc2, winstate->defineInitial)
+ {
+ name = strVal(lfirst(lc1)); /* DEFINE variable name */
+ initial = *(strVal(lfirst(lc2))); /* DEFINE variable initial */
+
+
+ if (!strcmp(name, vname))
+ return initial; /* found */
+ }
+ return 0;
+}
+
+/*
+ * string_set_init
+ * Create dynamic set of StringInfo.
+ */
+static
+StringSet *string_set_init(void)
+{
+/* Initial allocation size of str_set */
+#define STRING_SET_ALLOC_SIZE 1024
+
+ StringSet *string_set;
+ Size set_size;
+
+ string_set = palloc0(sizeof(StringSet));
+ string_set->set_index = 0;
+ set_size = STRING_SET_ALLOC_SIZE;
+ string_set->str_set = palloc(set_size * sizeof(StringInfo));
+ string_set->set_size = set_size;
+
+ return string_set;
+}
+
+/*
+ * Add StringInfo str to StringSet string_set.
+ */
+static
+void string_set_add(StringSet *string_set, StringInfo str)
+{
+ Size set_size;
+
+ set_size = string_set->set_size;
+ if (string_set->set_index >= set_size)
+ {
+ set_size *= 2;
+ string_set->str_set = repalloc(string_set->str_set,
+ set_size * sizeof(StringInfo));
+ string_set->set_size = set_size;
+ }
+
+ string_set->str_set[string_set->set_index++] = str;
+
+ return;
+}
+
+/*
+ * Returns StringInfo specified by index.
+ * If there's no data yet, returns NULL.
+ */
+static
+StringInfo string_set_get(StringSet *string_set, int index)
+{
+ /* no data? */
+ if (index == 0 && string_set->set_index == 0)
+ return NULL;
+
+ if (index < 0 ||index >= string_set->set_index)
+ elog(ERROR, "invalid index: %d", index);
+
+ return string_set->str_set[index];
+}
+
+/*
+ * Returns the size of StringSet.
+ */
+static
+int string_set_get_size(StringSet *string_set)
+{
+ return string_set->set_index;
+}
+
+/*
+ * Discard StringSet.
+ * All memory including StringSet itself is freed.
+ */
+static
+void string_set_discard(StringSet *string_set)
+{
+ int i;
+
+ for (i = 0; i < string_set->set_index; i++)
+ {
+ StringInfo str = string_set->str_set[i];
+ if (str)
+ {
+ pfree(str->data);
+ pfree(str);
+ }
+ }
+ pfree(string_set->str_set);
+ pfree(string_set);
+}
+
+/*
+ * Create and initialize variable postion structure
+ */
+static
+VariablePos *variable_pos_init(void)
+{
+ VariablePos *variable_pos;
+
+ variable_pos = palloc(sizeof(VariablePos) * NUM_ALPHABETS);
+ MemSet(variable_pos, -1, sizeof(VariablePos) * NUM_ALPHABETS);
+ return variable_pos;
+}
+
+/*
+ * Register pattern variable whose initial is initial into postion index.
+ * pos is position of initial.
+ * If pos is already registered, register it at next empty slot.
+ */
+static
+void variable_pos_register(VariablePos *variable_pos, char initial, int pos)
+{
+ int index = initial - 'a';
+ int slot;
+ int i;
+
+ if (pos < 0 || pos > NUM_ALPHABETS)
+ elog(ERROR, "initial is not valid char: %c", initial);
+
+ for (i = 0; i < NUM_ALPHABETS; i++)
+ {
+ slot = variable_pos[index].pos[i];
+ if (slot < 0)
+ {
+ /* empty slot found */
+ variable_pos[index].pos[i] = pos;
+ return;
+ }
+ }
+ elog(ERROR, "no empty slot for initial: %c", initial);
+}
+
+/*
+ * Returns true if initial1 can be followed by initial2
+ */
+static
+bool variable_pos_compare(VariablePos *variable_pos, char initial1, char initial2)
+{
+ int index1, index2;
+ int pos1, pos2;
+
+ for (index1 = 0; ; index1++)
+ {
+ pos1 = variable_pos_fetch(variable_pos, initial1, index1);
+ if (pos1 < 0)
+ break;
+
+ for (index2 = 0; ; index2++)
+ {
+ pos2 = variable_pos_fetch(variable_pos, initial2, index2);
+ if (pos2 < 0)
+ break;
+ if (pos1 <= pos2)
+ return true;
+ }
+ }
+ return false;
+}
+
+/*
+ * Fetch position of pattern variable whose initial is initial, and whose index
+ * is index. If no postion was registered by initial, index, returns -1.
+ */
+static
+int variable_pos_fetch(VariablePos *variable_pos, char initial, int index)
+{
+ int pos = initial - 'a';
+
+ if (pos < 0 || pos > NUM_ALPHABETS)
+ elog(ERROR, "initial is not valid char: %c", initial);
+
+ if (index < 0 || index > NUM_ALPHABETS)
+ elog(ERROR, "index is not valid: %d", index);
+
+ return variable_pos[pos].pos[index];
+}
+
+/*
+ * Discard VariablePos
+ */
+static
+void variable_pos_discard(VariablePos *variable_pos)
+{
+ pfree(variable_pos);
+}
diff --git a/src/backend/utils/adt/windowfuncs.c b/src/backend/utils/adt/windowfuncs.c
index 0bfbac00d7..a4a11c7f8d 100644
--- a/src/backend/utils/adt/windowfuncs.c
+++ b/src/backend/utils/adt/windowfuncs.c
@@ -13,6 +13,9 @@
*/
#include "postgres.h"
+#include "catalog/pg_collation_d.h"
+#include "executor/executor.h"
+#include "nodes/execnodes.h"
#include "nodes/parsenodes.h"
#include "nodes/supportnodes.h"
#include "utils/builtins.h"
@@ -37,11 +40,19 @@ typedef struct
int64 remainder; /* (total rows) % (bucket num) */
} ntile_context;
+/*
+ * rpr process information.
+ * Used for AFTER MATCH SKIP PAST LAST ROW
+ */
+typedef struct SkipContext
+{
+ int64 pos; /* last row absolute position */
+} SkipContext;
+
static bool rank_up(WindowObject winobj);
static Datum leadlag_common(FunctionCallInfo fcinfo,
bool forward, bool withoffset, bool withdefault);
-
/*
* utility routine for *_rank functions.
*/
@@ -674,7 +685,7 @@ window_last_value(PG_FUNCTION_ARGS)
bool isnull;
result = WinGetFuncArgInFrame(winobj, 0,
- 0, WINDOW_SEEK_TAIL, true,
+ 0, WINDOW_SEEK_TAIL, false,
&isnull, NULL);
if (isnull)
PG_RETURN_NULL();
@@ -714,3 +725,25 @@ window_nth_value(PG_FUNCTION_ARGS)
PG_RETURN_DATUM(result);
}
+
+/*
+ * prev
+ * Dummy function to invoke RPR's navigation operator "PREV".
+ * This is *not* a window function.
+ */
+Datum
+window_prev(PG_FUNCTION_ARGS)
+{
+ PG_RETURN_DATUM(PG_GETARG_DATUM(0));
+}
+
+/*
+ * next
+ * Dummy function to invoke RPR's navigation operation "NEXT".
+ * This is *not* a window function.
+ */
+Datum
+window_next(PG_FUNCTION_ARGS)
+{
+ PG_RETURN_DATUM(PG_GETARG_DATUM(0));
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f14aed422a..6df54a3cab 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10423,6 +10423,12 @@
{ oid => '3114', descr => 'fetch the Nth row value',
proname => 'nth_value', prokind => 'w', prorettype => 'anyelement',
proargtypes => 'anyelement int4', prosrc => 'window_nth_value' },
+{ oid => '6122', descr => 'previous value',
+ proname => 'prev', provolatile => 's', prorettype => 'anyelement',
+ proargtypes => 'anyelement', prosrc => 'window_prev' },
+{ oid => '6123', descr => 'next value',
+ proname => 'next', provolatile => 's', prorettype => 'anyelement',
+ proargtypes => 'anyelement', prosrc => 'window_next' },
# functions for range types
{ oid => '3832', descr => 'I/O',
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 5d7f17dee0..d8f92720bc 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -2470,6 +2470,11 @@ typedef enum WindowAggStatus
* tuples during spool */
} WindowAggStatus;
+#define RF_NOT_DETERMINED 0
+#define RF_FRAME_HEAD 1
+#define RF_SKIPPED 2
+#define RF_UNMATCHED 3
+
typedef struct WindowAggState
{
ScanState ss; /* its first field is NodeTag */
@@ -2518,6 +2523,15 @@ typedef struct WindowAggState
int64 groupheadpos; /* current row's peer group head position */
int64 grouptailpos; /* " " " " tail position (group end+1) */
+ /* these fields are used in Row pattern recognition: */
+ RPSkipTo rpSkipTo; /* Row Pattern Skip To type */
+ List *patternVariableList; /* list of row pattern variables names (list of String) */
+ List *patternRegexpList; /* list of row pattern regular expressions ('+' or ''. list of String) */
+ List *defineVariableList; /* list of row pattern definition variables (list of String) */
+ List *defineClauseList; /* expression for row pattern definition
+ * search conditions ExprState list */
+ List *defineInitial; /* list of row pattern definition variable initials (list of String) */
+
MemoryContext partcontext; /* context for partition-lifespan data */
MemoryContext aggcontext; /* shared context for aggregate working data */
MemoryContext curaggcontext; /* current aggregate's working data */
@@ -2554,6 +2568,18 @@ typedef struct WindowAggState
TupleTableSlot *agg_row_slot;
TupleTableSlot *temp_slot_1;
TupleTableSlot *temp_slot_2;
+
+ /* temporary slots for RPR */
+ TupleTableSlot *prev_slot; /* PREV row navigation operator */
+ TupleTableSlot *next_slot; /* NEXT row navigation operator */
+ TupleTableSlot *null_slot; /* all NULL slot */
+
+ /*
+ * Each byte corresponds to a row positioned at absolute its pos in
+ * partition. See above definition for RF_*
+ */
+ char *reduced_frame_map;
+ int64 alloc_sz; /* size of the map */
} WindowAggState;
/* ----------------
--
2.25.1
----Next_Part(Wed_Nov__8_16_37_05_2023_872)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v11-0005-Row-pattern-recognition-patch-docs.patch"
^ permalink raw reply [nested|flat] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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; 85+ 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] 85+ 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]>
0 siblings, 0 replies; 85+ 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] 85+ messages in thread
end of thread, other threads:[~2026-07-11 14:50 UTC | newest]
Thread overview: 85+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2023-11-08 06:57 [PATCH v11 4/7] Row pattern recognition patch (executor). Tatsuo Ishii <[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]>
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