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[PATCH 2/6] Move IS [NOT] NULL handling from BRIN support functions 4+ messages / 3 participants [nested] [flat]
* [PATCH 2/6] Move IS [NOT] NULL handling from BRIN support functions @ 2020-09-17 15:26 Tomas Vondra <[email protected]> 0 siblings, 0 replies; 4+ messages in thread From: Tomas Vondra @ 2020-09-17 15:26 UTC (permalink / raw) The handling of IS [NOT] NULL clauses is independent of an opclass, and most of the code was exactly the same in both minmax and inclusion. So instead move the code from support procedures to the AM methods etc. This simplifies the code quite a bit - especially the support procedures quite a bit, as they don't need to care about NULL values and flags at all. It also means the IS [NOT] NULL clauses can be evaluated without invoking the support procedure at all. Author: Tomas Vondra <[email protected]> Author: Nikita Glukhov <[email protected]> Reviewed-by: Alvaro Herrera <[email protected]> Reviewed-by: Mark Dilger <[email protected]> Reviewed-by: Alexander Korotkov <[email protected]> Reviewed-by: Masahiko Sawada <[email protected]> Reviewed-by: John Naylor <[email protected]> Discussion: https://postgr.es/m/[email protected] --- src/backend/access/brin/brin.c | 293 +++++++++++++++++------ src/backend/access/brin/brin_inclusion.c | 106 +------- src/backend/access/brin/brin_minmax.c | 103 +------- src/include/access/brin_internal.h | 3 + 4 files changed, 239 insertions(+), 266 deletions(-) diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c index dc187153aa..14da9ed17f 100644 --- a/src/backend/access/brin/brin.c +++ b/src/backend/access/brin/brin.c @@ -35,6 +35,7 @@ #include "storage/freespace.h" #include "utils/acl.h" #include "utils/builtins.h" +#include "utils/datum.h" #include "utils/index_selfuncs.h" #include "utils/memutils.h" #include "utils/rel.h" @@ -77,7 +78,9 @@ static void form_and_insert_tuple(BrinBuildState *state); static void union_tuples(BrinDesc *bdesc, BrinMemTuple *a, BrinTuple *b); static void brin_vacuum_scan(Relation idxrel, BufferAccessStrategy strategy); - +static bool add_values_to_range(Relation idxRel, BrinDesc *bdesc, + BrinMemTuple *dtup, Datum *values, bool *nulls); +static bool check_null_keys(BrinValues *bval, ScanKey *nullkeys, int nnullkeys); /* * BRIN handler function: return IndexAmRoutine with access method parameters @@ -179,7 +182,6 @@ brininsert(Relation idxRel, Datum *values, bool *nulls, OffsetNumber off; BrinTuple *brtup; BrinMemTuple *dtup; - int keyno; CHECK_FOR_INTERRUPTS(); @@ -243,31 +245,7 @@ brininsert(Relation idxRel, Datum *values, bool *nulls, dtup = brin_deform_tuple(bdesc, brtup, NULL); - /* - * Compare the key values of the new tuple to the stored index values; - * our deformed tuple will get updated if the new tuple doesn't fit - * the original range (note this means we can't break out of the loop - * early). Make a note of whether this happens, so that we know to - * insert the modified tuple later. - */ - for (keyno = 0; keyno < bdesc->bd_tupdesc->natts; keyno++) - { - Datum result; - BrinValues *bval; - FmgrInfo *addValue; - - bval = &dtup->bt_columns[keyno]; - addValue = index_getprocinfo(idxRel, keyno + 1, - BRIN_PROCNUM_ADDVALUE); - result = FunctionCall4Coll(addValue, - idxRel->rd_indcollation[keyno], - PointerGetDatum(bdesc), - PointerGetDatum(bval), - values[keyno], - nulls[keyno]); - /* if that returned true, we need to insert the updated tuple */ - need_insert |= DatumGetBool(result); - } + need_insert = add_values_to_range(idxRel, bdesc, dtup, values, nulls); if (!need_insert) { @@ -390,8 +368,10 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm) BrinMemTuple *dtup; BrinTuple *btup = NULL; Size btupsz = 0; - ScanKey **keys; - int *nkeys; + ScanKey **keys, + **nullkeys; + int *nkeys, + *nnullkeys; int keyno; opaque = (BrinOpaque *) scan->opaque; @@ -416,10 +396,13 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm) /* * Make room for per-attribute lists of scan keys that we'll pass to the - * consistent support procedure. + * consistent support procedure. We keep null and regular keys separate, + * so that we can easily pass regular keys to the consistent function. */ keys = palloc0(sizeof(ScanKey *) * bdesc->bd_tupdesc->natts); + nullkeys = palloc0(sizeof(ScanKey *) * bdesc->bd_tupdesc->natts); nkeys = palloc0(sizeof(int) * bdesc->bd_tupdesc->natts); + nnullkeys = palloc0(sizeof(int) * bdesc->bd_tupdesc->natts); /* * Preprocess the scan keys - split them into per-attribute arrays. @@ -440,23 +423,24 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm) TupleDescAttr(bdesc->bd_tupdesc, keyattno - 1)->attcollation)); - /* First time we see this index attribute, so init as needed. */ - if (!keys[keyattno-1]) + /* + * First time we see this index attribute, so init as needed. + * + * This is a bit of an overkill - we don't know how many scan + * keys are there for a given attribute, so we simply allocate + * the largest number possible (as if all scan keys belonged to + * the same attribute). This may waste a bit of memory, but we + * only expect small number of scan keys in general, so this + * should be negligible, and it's probably cheaper than having + * to repalloc repeatedly. + */ + if (consistentFn[keyattno - 1].fn_oid == InvalidOid) { FmgrInfo *tmp; - /* - * This is a bit of an overkill - we don't know how many - * scan keys are there for this attribute, so we simply - * allocate the largest number possible. This may waste - * a bit of memory, but we only expect small number of - * scan keys in general, so this should be negligible, - * and it's cheaper than having to repalloc repeatedly. - */ - keys[keyattno - 1] = palloc0(sizeof(ScanKey) * scan->numberOfKeys); - - /* First time this column, so look up consistent function */ - Assert(consistentFn[keyattno - 1].fn_oid == InvalidOid); + /* No key/null arrays for this attribute. */ + Assert((keys[keyattno - 1] == NULL) && (nkeys[keyattno - 1] == 0)); + Assert((nullkeys[keyattno - 1] == NULL) && (nnullkeys[keyattno - 1] == 0)); tmp = index_getprocinfo(idxRel, keyattno, BRIN_PROCNUM_CONSISTENT); @@ -464,9 +448,23 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm) CurrentMemoryContext); } - /* Add key to the per-attribute array. */ - keys[keyattno - 1][nkeys[keyattno - 1]] = key; - nkeys[keyattno - 1]++; + /* Add key to the proper per-attribute array. */ + if (key->sk_flags & SK_ISNULL) + { + if (!nullkeys[keyattno - 1]) + nullkeys[keyattno - 1] = palloc0(sizeof(ScanKey) * scan->numberOfKeys); + + nullkeys[keyattno - 1][nnullkeys[keyattno - 1]] = key; + nnullkeys[keyattno - 1]++; + } + else + { + if (!keys[keyattno - 1]) + keys[keyattno - 1] = palloc0(sizeof(ScanKey) * scan->numberOfKeys); + + keys[keyattno - 1][nkeys[keyattno - 1]] = key; + nkeys[keyattno - 1]++; + } } /* allocate an initial in-memory tuple, out of the per-range memcxt */ @@ -544,15 +542,57 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm) BrinValues *bval; Datum add; - /* skip attributes without any san keys */ - if (nkeys[attno - 1] == 0) + /* + * skip attributes without any scan keys (both regular + * and IS [NOT] NULL) + */ + if (nkeys[attno - 1] == 0 && nnullkeys[attno - 1] == 0) continue; bval = &dtup->bt_columns[attno - 1]; + /* + * First check if there are any IS [NOT] NULL scan keys, + * and if we're violating them. In that case we can + * terminate early, without invoking the support function. + * + * As there may be more keys, we can only detemine mismatch + * within this loop. + */ + if (bdesc->bd_info[attno - 1]->oi_regular_nulls && + !check_null_keys(bval, nullkeys[attno - 1], + nnullkeys[attno - 1])) + { + /* + * If any of the IS [NOT] NULL keys failed, the page + * range as a whole can't pass. So terminate the loop. + */ + addrange = false; + break; + } + + /* + * So either there are no IS [NOT] NULL keys, or all passed. + * If there are no regular scan keys, we're done - the page + * range matches. If there are regular keys, but the page + * range is marked as 'all nulls' it can't possibly pass + * (we're assuming the operators are strict). + */ + + /* No regular scan keys - page range as a whole passes. */ + if (!nkeys[attno - 1]) + continue; + Assert((nkeys[attno - 1] > 0) && (nkeys[attno - 1] <= scan->numberOfKeys)); + /* If it is all nulls, it cannot possibly be consistent. */ + if (bval->bv_allnulls) + { + addrange = false; + break; + } + /* * Check whether the scan key is consistent with the page * range values; if so, have the pages in the range added @@ -695,7 +735,6 @@ brinbuildCallback(Relation index, { BrinBuildState *state = (BrinBuildState *) brstate; BlockNumber thisblock; - int i; thisblock = ItemPointerGetBlockNumber(tid); @@ -724,25 +763,8 @@ brinbuildCallback(Relation index, } /* Accumulate the current tuple into the running state */ - for (i = 0; i < state->bs_bdesc->bd_tupdesc->natts; i++) - { - FmgrInfo *addValue; - BrinValues *col; - Form_pg_attribute attr = TupleDescAttr(state->bs_bdesc->bd_tupdesc, i); - - col = &state->bs_dtuple->bt_columns[i]; - addValue = index_getprocinfo(index, i + 1, - BRIN_PROCNUM_ADDVALUE); - - /* - * Update dtuple state, if and as necessary. - */ - FunctionCall4Coll(addValue, - attr->attcollation, - PointerGetDatum(state->bs_bdesc), - PointerGetDatum(col), - values[i], isnull[i]); - } + (void) add_values_to_range(index, state->bs_bdesc, state->bs_dtuple, + values, isnull); } /* @@ -1521,6 +1543,39 @@ union_tuples(BrinDesc *bdesc, BrinMemTuple *a, BrinTuple *b) FmgrInfo *unionFn; BrinValues *col_a = &a->bt_columns[keyno]; BrinValues *col_b = &db->bt_columns[keyno]; + BrinOpcInfo *opcinfo = bdesc->bd_info[keyno]; + + if (opcinfo->oi_regular_nulls) + { + /* Adjust "hasnulls". */ + if (!col_a->bv_hasnulls && col_b->bv_hasnulls) + col_a->bv_hasnulls = true; + + /* If there are no values in B, there's nothing left to do. */ + if (col_b->bv_allnulls) + continue; + + /* + * Adjust "allnulls". If A doesn't have values, just copy the + * values from B into A, and we're done. We cannot run the + * operators in this case, because values in A might contain + * garbage. Note we already established that B contains values. + */ + if (col_a->bv_allnulls) + { + int i; + + col_a->bv_allnulls = false; + + for (i = 0; i < opcinfo->oi_nstored; i++) + col_a->bv_values[i] = + datumCopy(col_b->bv_values[i], + opcinfo->oi_typcache[i]->typbyval, + opcinfo->oi_typcache[i]->typlen); + + continue; + } + } unionFn = index_getprocinfo(bdesc->bd_index, keyno + 1, BRIN_PROCNUM_UNION); @@ -1574,3 +1629,103 @@ brin_vacuum_scan(Relation idxrel, BufferAccessStrategy strategy) */ FreeSpaceMapVacuum(idxrel); } + +static bool +add_values_to_range(Relation idxRel, BrinDesc *bdesc, BrinMemTuple *dtup, + Datum *values, bool *nulls) +{ + int keyno; + bool modified = false; + + /* + * Compare the key values of the new tuple to the stored index values; + * our deformed tuple will get updated if the new tuple doesn't fit + * the original range (note this means we can't break out of the loop + * early). Make a note of whether this happens, so that we know to + * insert the modified tuple later. + */ + for (keyno = 0; keyno < bdesc->bd_tupdesc->natts; keyno++) + { + Datum result; + BrinValues *bval; + FmgrInfo *addValue; + + bval = &dtup->bt_columns[keyno]; + + if (bdesc->bd_info[keyno]->oi_regular_nulls && nulls[keyno]) + { + /* + * If the new value is null, we record that we saw it if it's + * the first one; otherwise, there's nothing to do. + */ + if (!bval->bv_hasnulls) + { + bval->bv_hasnulls = true; + modified = true; + } + + continue; + } + + addValue = index_getprocinfo(idxRel, keyno + 1, + BRIN_PROCNUM_ADDVALUE); + result = FunctionCall4Coll(addValue, + idxRel->rd_indcollation[keyno], + PointerGetDatum(bdesc), + PointerGetDatum(bval), + values[keyno], + nulls[keyno]); + /* if that returned true, we need to insert the updated tuple */ + modified |= DatumGetBool(result); + } + + return modified; +} + +static bool +check_null_keys(BrinValues *bval, ScanKey *nullkeys, int nnullkeys) +{ + int keyno; + + /* + * First check if there are any IS [NOT] NULL scan keys, and if we're + * violating them. + */ + for (keyno = 0; keyno < nnullkeys; keyno++) + { + ScanKey key = nullkeys[keyno]; + + Assert(key->sk_attno == bval->bv_attno); + + /* Handle only IS NULL/IS NOT NULL tests */ + if (!(key->sk_flags & SK_ISNULL)) + continue; + + if (key->sk_flags & SK_SEARCHNULL) + { + /* IS NULL scan key, but range has no NULLs */ + if (!bval->bv_allnulls && !bval->bv_hasnulls) + return false; + } + else if (key->sk_flags & SK_SEARCHNOTNULL) + { + /* + * For IS NOT NULL, we can only skip ranges that are known to + * have only nulls. + */ + if (bval->bv_allnulls) + return false; + } + else + { + /* + * Neither IS NULL nor IS NOT NULL was used; assume all indexable + * operators are strict and thus return false with NULL value in + * the scan key. + */ + return false; + } + } + + return true; +} diff --git a/src/backend/access/brin/brin_inclusion.c b/src/backend/access/brin/brin_inclusion.c index 215bc794d3..f4730be3b9 100644 --- a/src/backend/access/brin/brin_inclusion.c +++ b/src/backend/access/brin/brin_inclusion.c @@ -110,6 +110,7 @@ brin_inclusion_opcinfo(PG_FUNCTION_ARGS) */ result = palloc0(MAXALIGN(SizeofBrinOpcInfo(3)) + sizeof(InclusionOpaque)); result->oi_nstored = 3; + result->oi_regular_nulls = true; result->oi_opaque = (InclusionOpaque *) MAXALIGN((char *) result + SizeofBrinOpcInfo(3)); @@ -141,7 +142,7 @@ brin_inclusion_add_value(PG_FUNCTION_ARGS) BrinDesc *bdesc = (BrinDesc *) PG_GETARG_POINTER(0); BrinValues *column = (BrinValues *) PG_GETARG_POINTER(1); Datum newval = PG_GETARG_DATUM(2); - bool isnull = PG_GETARG_BOOL(3); + bool isnull PG_USED_FOR_ASSERTS_ONLY = PG_GETARG_BOOL(3); Oid colloid = PG_GET_COLLATION(); FmgrInfo *finfo; Datum result; @@ -149,18 +150,7 @@ brin_inclusion_add_value(PG_FUNCTION_ARGS) AttrNumber attno; Form_pg_attribute attr; - /* - * If the new value is null, we record that we saw it if it's the first - * one; otherwise, there's nothing to do. - */ - if (isnull) - { - if (column->bv_hasnulls) - PG_RETURN_BOOL(false); - - column->bv_hasnulls = true; - PG_RETURN_BOOL(true); - } + Assert(!isnull); attno = column->bv_attno; attr = TupleDescAttr(bdesc->bd_tupdesc, attno - 1); @@ -264,63 +254,6 @@ brin_inclusion_consistent(PG_FUNCTION_ARGS) int nkeys = PG_GETARG_INT32(3); Oid colloid = PG_GET_COLLATION(); int keyno; - bool regular_keys = false; - - /* - * First check if there are any IS NULL scan keys, and if we're - * violating them. In that case we can terminate early, without - * inspecting the ranges. - */ - for (keyno = 0; keyno < nkeys; keyno++) - { - ScanKey key = keys[keyno]; - - Assert(key->sk_attno == column->bv_attno); - - /* handle IS NULL/IS NOT NULL tests */ - if (key->sk_flags & SK_ISNULL) - { - if (key->sk_flags & SK_SEARCHNULL) - { - if (column->bv_allnulls || column->bv_hasnulls) - continue; /* this key is fine, continue */ - - PG_RETURN_BOOL(false); - } - - /* - * For IS NOT NULL, we can only skip ranges that are known to have - * only nulls. - */ - if (key->sk_flags & SK_SEARCHNOTNULL) - { - if (column->bv_allnulls) - PG_RETURN_BOOL(false); - - continue; - } - - /* - * Neither IS NULL nor IS NOT NULL was used; assume all indexable - * operators are strict and return false. - */ - PG_RETURN_BOOL(false); - } - else - /* note we have regular (non-NULL) scan keys */ - regular_keys = true; - } - - /* - * If the page range is all nulls, it cannot possibly be consistent if - * there are some regular scan keys. - */ - if (column->bv_allnulls && regular_keys) - PG_RETURN_BOOL(false); - - /* If there are no regular keys, the page range is considered consistent. */ - if (!regular_keys) - PG_RETURN_BOOL(true); /* It has to be checked, if it contains elements that are not mergeable. */ if (DatumGetBool(column->bv_values[INCLUSION_UNMERGEABLE])) @@ -331,9 +264,8 @@ brin_inclusion_consistent(PG_FUNCTION_ARGS) { ScanKey key = keys[keyno]; - /* ignore IS NULL/IS NOT NULL tests handled above */ - if (key->sk_flags & SK_ISNULL) - continue; + /* NULL keys are handled and filtered-out in bringetbitmap */ + Assert(!(key->sk_flags & SK_ISNULL)); /* * When there are multiple scan keys, failure to meet the @@ -572,37 +504,11 @@ brin_inclusion_union(PG_FUNCTION_ARGS) Datum result; Assert(col_a->bv_attno == col_b->bv_attno); - - /* Adjust "hasnulls". */ - if (!col_a->bv_hasnulls && col_b->bv_hasnulls) - col_a->bv_hasnulls = true; - - /* If there are no values in B, there's nothing left to do. */ - if (col_b->bv_allnulls) - PG_RETURN_VOID(); + Assert(!col_a->bv_allnulls && !col_b->bv_allnulls); attno = col_a->bv_attno; attr = TupleDescAttr(bdesc->bd_tupdesc, attno - 1); - /* - * Adjust "allnulls". If A doesn't have values, just copy the values from - * B into A, and we're done. We cannot run the operators in this case, - * because values in A might contain garbage. Note we already established - * that B contains values. - */ - if (col_a->bv_allnulls) - { - col_a->bv_allnulls = false; - col_a->bv_values[INCLUSION_UNION] = - datumCopy(col_b->bv_values[INCLUSION_UNION], - attr->attbyval, attr->attlen); - col_a->bv_values[INCLUSION_UNMERGEABLE] = - col_b->bv_values[INCLUSION_UNMERGEABLE]; - col_a->bv_values[INCLUSION_CONTAINS_EMPTY] = - col_b->bv_values[INCLUSION_CONTAINS_EMPTY]; - PG_RETURN_VOID(); - } - /* If B includes empty elements, mark A similarly, if needed. */ if (!DatumGetBool(col_a->bv_values[INCLUSION_CONTAINS_EMPTY]) && DatumGetBool(col_b->bv_values[INCLUSION_CONTAINS_EMPTY])) diff --git a/src/backend/access/brin/brin_minmax.c b/src/backend/access/brin/brin_minmax.c index 12878ff3a0..6c8852d404 100644 --- a/src/backend/access/brin/brin_minmax.c +++ b/src/backend/access/brin/brin_minmax.c @@ -48,6 +48,7 @@ brin_minmax_opcinfo(PG_FUNCTION_ARGS) result = palloc0(MAXALIGN(SizeofBrinOpcInfo(2)) + sizeof(MinmaxOpaque)); result->oi_nstored = 2; + result->oi_regular_nulls = true; result->oi_opaque = (MinmaxOpaque *) MAXALIGN((char *) result + SizeofBrinOpcInfo(2)); result->oi_typcache[0] = result->oi_typcache[1] = @@ -69,7 +70,7 @@ brin_minmax_add_value(PG_FUNCTION_ARGS) BrinDesc *bdesc = (BrinDesc *) PG_GETARG_POINTER(0); BrinValues *column = (BrinValues *) PG_GETARG_POINTER(1); Datum newval = PG_GETARG_DATUM(2); - bool isnull = PG_GETARG_DATUM(3); + bool isnull PG_USED_FOR_ASSERTS_ONLY = PG_GETARG_DATUM(3); Oid colloid = PG_GET_COLLATION(); FmgrInfo *cmpFn; Datum compar; @@ -77,18 +78,7 @@ brin_minmax_add_value(PG_FUNCTION_ARGS) Form_pg_attribute attr; AttrNumber attno; - /* - * If the new value is null, we record that we saw it if it's the first - * one; otherwise, there's nothing to do. - */ - if (isnull) - { - if (column->bv_hasnulls) - PG_RETURN_BOOL(false); - - column->bv_hasnulls = true; - PG_RETURN_BOOL(true); - } + Assert(!isnull); attno = column->bv_attno; attr = TupleDescAttr(bdesc->bd_tupdesc, attno - 1); @@ -152,72 +142,14 @@ brin_minmax_consistent(PG_FUNCTION_ARGS) int nkeys = PG_GETARG_INT32(3); Oid colloid = PG_GET_COLLATION(); int keyno; - bool regular_keys = false; - - /* - * First check if there are any IS NULL scan keys, and if we're - * violating them. In that case we can terminate early, without - * inspecting the ranges. - */ - for (keyno = 0; keyno < nkeys; keyno++) - { - ScanKey key = keys[keyno]; - - Assert(key->sk_attno == column->bv_attno); - - /* handle IS NULL/IS NOT NULL tests */ - if (key->sk_flags & SK_ISNULL) - { - if (key->sk_flags & SK_SEARCHNULL) - { - if (column->bv_allnulls || column->bv_hasnulls) - continue; /* this key is fine, continue */ - - PG_RETURN_BOOL(false); - } - - /* - * For IS NOT NULL, we can only skip ranges that are known to have - * only nulls. - */ - if (key->sk_flags & SK_SEARCHNOTNULL) - { - if (column->bv_allnulls) - PG_RETURN_BOOL(false); - - continue; - } - - /* - * Neither IS NULL nor IS NOT NULL was used; assume all indexable - * operators are strict and return false. - */ - PG_RETURN_BOOL(false); - } - else - /* note we have regular (non-NULL) scan keys */ - regular_keys = true; - } - - /* - * If the page range is all nulls, it cannot possibly be consistent if - * there are some regular scan keys. - */ - if (column->bv_allnulls && regular_keys) - PG_RETURN_BOOL(false); - - /* If there are no regular keys, the page range is considered consistent. */ - if (!regular_keys) - PG_RETURN_BOOL(true); /* Check that the range is consistent with all scan keys. */ for (keyno = 0; keyno < nkeys; keyno++) { ScanKey key = keys[keyno]; - /* ignore IS NULL/IS NOT NULL tests handled above */ - if (key->sk_flags & SK_ISNULL) - continue; + /* NULL keys are handled and filtered-out in bringetbitmap */ + Assert(!(key->sk_flags & SK_ISNULL)); /* * When there are multiple scan keys, failure to meet the @@ -308,34 +240,11 @@ brin_minmax_union(PG_FUNCTION_ARGS) bool needsadj; Assert(col_a->bv_attno == col_b->bv_attno); - - /* Adjust "hasnulls" */ - if (!col_a->bv_hasnulls && col_b->bv_hasnulls) - col_a->bv_hasnulls = true; - - /* If there are no values in B, there's nothing left to do */ - if (col_b->bv_allnulls) - PG_RETURN_VOID(); + Assert(!col_a->bv_allnulls && !col_b->bv_allnulls); attno = col_a->bv_attno; attr = TupleDescAttr(bdesc->bd_tupdesc, attno - 1); - /* - * Adjust "allnulls". If A doesn't have values, just copy the values from - * B into A, and we're done. We cannot run the operators in this case, - * because values in A might contain garbage. Note we already established - * that B contains values. - */ - if (col_a->bv_allnulls) - { - col_a->bv_allnulls = false; - col_a->bv_values[0] = datumCopy(col_b->bv_values[0], - attr->attbyval, attr->attlen); - col_a->bv_values[1] = datumCopy(col_b->bv_values[1], - attr->attbyval, attr->attlen); - PG_RETURN_VOID(); - } - /* Adjust minimum, if B's min is less than A's min */ finfo = minmax_get_strategy_procinfo(bdesc, attno, attr->atttypid, BTLessStrategyNumber); diff --git a/src/include/access/brin_internal.h b/src/include/access/brin_internal.h index 78c89a6961..79440ebe7b 100644 --- a/src/include/access/brin_internal.h +++ b/src/include/access/brin_internal.h @@ -27,6 +27,9 @@ typedef struct BrinOpcInfo /* Number of columns stored in an index column of this opclass */ uint16 oi_nstored; + /* Regular processing of NULLs in BrinValues? */ + bool oi_regular_nulls; + /* Opaque pointer for the opclass' private use */ void *oi_opaque; -- 2.26.2 --------------310A2AE1CC4C2E2E77559E3D Content-Type: text/x-patch; charset=UTF-8; name="0003-Optimize-allocations-in-bringetbitmap-20210114-2.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0003-Optimize-allocations-in-bringetbitmap-20210114-2.patch" ^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: pg_resetwal: Corrections around -c option @ 2023-10-09 15:48 Alvaro Herrera <[email protected]> 2023-10-10 07:30 ` Re: pg_resetwal: Corrections around -c option Peter Eisentraut <[email protected]> 0 siblings, 1 reply; 4+ messages in thread From: Alvaro Herrera @ 2023-10-09 15:48 UTC (permalink / raw) To: Peter Eisentraut <[email protected]>; +Cc: pgsql-hackers On 2023-Sep-28, Peter Eisentraut wrote: > Branching off from [0], here is a for-discussion patch about some > corrections for the pg_resetwal -c (--commit-timestamp-ids) option. > > First, in the documentation for finding a manual value for the -c option > based on the files present in the data directory, it was missing a > multiplier, like for the other SLRU-based values, and also missing the > mention of adding one for the upper value. The value I came up with is > computed as > > SLRU_PAGES_PER_SEGMENT * COMMIT_TS_XACTS_PER_PAGE = 13088 = 0x3320 Hmm, not sure about this. SLRU_PAGES_PER_SEGMENT is 32, and COMMIT_TS_XACTS_PER_PAGE is 819, so this formula gives decimal 26208 = 0x6660. But more generally, I'm not sure about the algorithm. Really, the safe value also depends on how large the latest file actually is; e.g., if your numerically greatest file is only 32kB long (four pages) then you can't specify values that refer to Xids in pages 5 and beyond, because those pages will not have been zeroed into existence yet, so you'll get an error: ERROR: could not access status of transaction 55692 DETAIL: Could not read from file "pg_commit_ts/0002" at offset 32768: read too few bytes. I think a useful value can be had by multiplying 26208 by the latest *complete* file number, then if there is an incomplete last file, add 819 multiplied by the number of pages in it. Also, "numerically greatest" is the wrong thing in case you've recently wrapped XIDs around but the oldest files (before the wraparound) are still present. You really want the "logically latest" files. (I think that'll coincide with the files having the latest modification times.) Not sure how to write this concisely, though. Should we really try? (I think the number 13088 appeared somewhere in connection with multixacts. Maybe there was a confusion with that.) > Second, the present pg_resetwal code hardcodes the minimum value as 2, which > is FrozenTransactionId, but it's not clear why that is allowed. Maybe we > should change that to FirstNormalTransactionId, which matches other > xid-related options in pg_resetwal. Yes, that's clearly a mistake I made at the last minute: in [1] I posted this patch *without* the test for 2, and when I pushed the patch two days later, I had introduced that without any further explanation. BTW if you `git show 666e8db` (which is the SHA1 identifier for pg_resetxlog.c that appears in the patch I posted back then) you'll see that the existing code did not have any similar protection for valid XID values. The tests to FirstNormalTransactionId for -u and -x were introduced by commit 74cf7d46a91d, seven years later -- that commit both introduced -u as a new feature, and hardened the tests for -x, which was previously only testing for zero. [1] https://postgr.es/m/[email protected] -- Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/ "Las navajas y los monos deben estar siempre distantes" (Germán Poo) ^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: pg_resetwal: Corrections around -c option 2023-10-09 15:48 Re: pg_resetwal: Corrections around -c option Alvaro Herrera <[email protected]> @ 2023-10-10 07:30 ` Peter Eisentraut <[email protected]> 2023-10-10 10:53 ` Re: pg_resetwal: Corrections around -c option Alvaro Herrera <[email protected]> 0 siblings, 1 reply; 4+ messages in thread From: Peter Eisentraut @ 2023-10-10 07:30 UTC (permalink / raw) To: Alvaro Herrera <[email protected]>; +Cc: pgsql-hackers On 09.10.23 17:48, Alvaro Herrera wrote: > Hmm, not sure about this. SLRU_PAGES_PER_SEGMENT is 32, and > COMMIT_TS_XACTS_PER_PAGE is 819, so this formula gives decimal 26208 = > 0x6660. But more generally, I'm not sure about the algorithm. Really, > the safe value also depends on how large the latest file actually is; > e.g., if your numerically greatest file is only 32kB long (four pages) > then you can't specify values that refer to Xids in pages 5 and beyond, > because those pages will not have been zeroed into existence yet, so > you'll get an error: > ERROR: could not access status of transaction 55692 > DETAIL: Could not read from file "pg_commit_ts/0002" at offset 32768: read too few bytes. > I think a useful value can be had by multiplying 26208 by the latest > *complete* file number, then if there is an incomplete last file, add > 819 multiplied by the number of pages in it. > > Also, "numerically greatest" is the wrong thing in case you've recently > wrapped XIDs around but the oldest files (before the wraparound) are > still present. You really want the "logically latest" files. (I think > that'll coincide with the files having the latest modification times.) Would those issues also apply to the other SLRU-based guides on this man page? Are they all a bit wrong? > Not sure how to write this concisely, though. Should we really try? Maybe not. But the documentation currently suggests you can try (probably somewhat copy-and-pasted). >> Second, the present pg_resetwal code hardcodes the minimum value as 2, which >> is FrozenTransactionId, but it's not clear why that is allowed. Maybe we >> should change that to FirstNormalTransactionId, which matches other >> xid-related options in pg_resetwal. > > Yes, that's clearly a mistake I made at the last minute: in [1] I posted > this patch *without* the test for 2, and when I pushed the patch two > days later, I had introduced that without any further explanation. > > BTW if you `git show 666e8db` (which is the SHA1 identifier for > pg_resetxlog.c that appears in the patch I posted back then) you'll see > that the existing code did not have any similar protection for valid XID > values. The tests to FirstNormalTransactionId for -u and -x were > introduced by commit 74cf7d46a91d, seven years later -- that commit both > introduced -u as a new feature, and hardened the tests for -x, which was > previously only testing for zero. I have committed this. ^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: pg_resetwal: Corrections around -c option 2023-10-09 15:48 Re: pg_resetwal: Corrections around -c option Alvaro Herrera <[email protected]> 2023-10-10 07:30 ` Re: pg_resetwal: Corrections around -c option Peter Eisentraut <[email protected]> @ 2023-10-10 10:53 ` Alvaro Herrera <[email protected]> 0 siblings, 0 replies; 4+ messages in thread From: Alvaro Herrera @ 2023-10-10 10:53 UTC (permalink / raw) To: Peter Eisentraut <[email protected]>; +Cc: pgsql-hackers On 2023-Oct-10, Peter Eisentraut wrote: > On 09.10.23 17:48, Alvaro Herrera wrote: > > Hmm, not sure about this. [...] > > Would those issues also apply to the other SLRU-based guides on this man > page? Are they all a bit wrong? I didn't verify, but I think it's likely that they do and they are. > > Not sure how to write this concisely, though. Should we really try? > > Maybe not. But the documentation currently suggests you can try (probably > somewhat copy-and-pasted). I bet this has not been thoroughly verified. Perhaps we should have (somewhere outside the option list) a separate paragraph that explains how to determine the safest maximum value to use, and list only the multiplier together with each option. -- Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/ ^ permalink raw reply [nested|flat] 4+ messages in thread
end of thread, other threads:[~2023-10-10 10:53 UTC | newest] Thread overview: 4+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2020-09-17 15:26 [PATCH 2/6] Move IS [NOT] NULL handling from BRIN support functions Tomas Vondra <[email protected]> 2023-10-09 15:48 Re: pg_resetwal: Corrections around -c option Alvaro Herrera <[email protected]> 2023-10-10 07:30 ` Re: pg_resetwal: Corrections around -c option Peter Eisentraut <[email protected]> 2023-10-10 10:53 ` Re: pg_resetwal: Corrections around -c option Alvaro Herrera <[email protected]>
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