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[PATCH 8/8] Ignore correlation for new BRIN opclasses 3+ messages / 3 participants [nested] [flat]
* [PATCH 8/8] Ignore correlation for new BRIN opclasses @ 2020-09-12 13:07 Tomas Vondra <[email protected]> 0 siblings, 0 replies; 3+ messages in thread From: Tomas Vondra @ 2020-09-12 13:07 UTC (permalink / raw) The new BRIN opclasses (bloom and minmax-multi) are less sensitive to poorly correlated data, so just assume the data is perfectly correlated during costing. Author: Tomas Vondra <[email protected]> Discussion: https://postgr.es/m/[email protected] --- src/backend/access/brin/brin_bloom.c | 1 + src/backend/access/brin/brin_minmax_multi.c | 1 + src/backend/utils/adt/selfuncs.c | 19 ++++++++++++++++++- src/include/access/brin_internal.h | 3 +++ 4 files changed, 23 insertions(+), 1 deletion(-) diff --git a/src/backend/access/brin/brin_bloom.c b/src/backend/access/brin/brin_bloom.c index c086e83236..22590b2351 100644 --- a/src/backend/access/brin/brin_bloom.c +++ b/src/backend/access/brin/brin_bloom.c @@ -412,6 +412,7 @@ brin_bloom_opcinfo(PG_FUNCTION_ARGS) result = palloc0(MAXALIGN(SizeofBrinOpcInfo(1)) + sizeof(BloomOpaque)); + result->oi_ignore_correlation = true; result->oi_nstored = 1; result->oi_regular_nulls = true; result->oi_opaque = (BloomOpaque *) diff --git a/src/backend/access/brin/brin_minmax_multi.c b/src/backend/access/brin/brin_minmax_multi.c index d2dc38adc8..6b1dd1040c 100644 --- a/src/backend/access/brin/brin_minmax_multi.c +++ b/src/backend/access/brin/brin_minmax_multi.c @@ -1737,6 +1737,7 @@ brin_minmax_multi_opcinfo(PG_FUNCTION_ARGS) result = palloc0(MAXALIGN(SizeofBrinOpcInfo(1)) + sizeof(MinmaxMultiOpaque)); + result->oi_ignore_correlation = true; result->oi_nstored = 1; result->oi_regular_nulls = true; result->oi_opaque = (MinmaxMultiOpaque *) diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index 52314d3aa1..0320d128f6 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -98,6 +98,7 @@ #include <math.h> #include "access/brin.h" +#include "access/brin_internal.h" #include "access/brin_page.h" #include "access/gin.h" #include "access/table.h" @@ -7352,7 +7353,8 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count, double minimalRanges; double estimatedRanges; double selec; - Relation indexRel; + Relation indexRel = NULL; + TupleDesc tupdesc = NULL; ListCell *l; VariableStatData vardata; @@ -7374,6 +7376,7 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count, */ indexRel = index_open(index->indexoid, NoLock); brinGetStats(indexRel, &statsData); + tupdesc = RelationGetDescr(indexRel); index_close(indexRel, NoLock); /* work out the actual number of ranges in the index */ @@ -7407,6 +7410,17 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count, { IndexClause *iclause = lfirst_node(IndexClause, l); AttrNumber attnum = index->indexkeys[iclause->indexcol]; + FmgrInfo *opcInfoFn; + BrinOpcInfo *opcInfo; + Form_pg_attribute attr = TupleDescAttr(tupdesc, iclause->indexcol); + bool ignore_correlation; + + opcInfoFn = index_getprocinfo(indexRel, iclause->indexcol + 1, BRIN_PROCNUM_OPCINFO); + + opcInfo = (BrinOpcInfo *) + DatumGetPointer(FunctionCall1(opcInfoFn, attr->atttypid)); + + ignore_correlation = opcInfo->oi_ignore_correlation; /* attempt to lookup stats in relation for this index column */ if (attnum != 0) @@ -7477,6 +7491,9 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count, if (sslot.nnumbers > 0) varCorrelation = Abs(sslot.numbers[0]); + if (ignore_correlation) + varCorrelation = 1.0; + if (varCorrelation > *indexCorrelation) *indexCorrelation = varCorrelation; diff --git a/src/include/access/brin_internal.h b/src/include/access/brin_internal.h index 89254b5766..063b703208 100644 --- a/src/include/access/brin_internal.h +++ b/src/include/access/brin_internal.h @@ -30,6 +30,9 @@ typedef struct BrinOpcInfo /* Regular processing of NULLs in BrinValues? */ bool oi_regular_nulls; + /* Ignore correlation during cost estimation */ + bool oi_ignore_correlation; + /* Opaque pointer for the opclass' private use */ void *oi_opaque; -- 2.26.2 --------------82D677E9F94AC7574E460205-- ^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Correct comment wording in extension.c @ 2026-01-13 05:40 John Naylor <[email protected]> 2026-01-13 06:31 ` Re: Correct comment wording in extension.c Chao Li <[email protected]> 0 siblings, 1 reply; 3+ messages in thread From: John Naylor @ 2026-01-13 05:40 UTC (permalink / raw) To: Chao Li <[email protected]>; +Cc: li carol <[email protected]>; albert tan <[email protected]>; [email protected] <[email protected]> On Sun, Jan 11, 2026 at 11:58 AM Chao Li <[email protected]> wrote: > v4-0001 looks good to me. When I say I'm going to commit "unless/barring", no response is necessary unless there is a problem. > I just went through extension.c and got a few more comment improvements. I put them in v5-0002, please take a look. - * for them therefore uses about O(N^2) time when there are N versions of + * for them therefore uses O(N^2) time when there are N versions of - /* store the OID of the namespace to-be-changed */ + /* store the OID of the namespace to be changed */ Please read these responses to you from last week: https://www.postgresql.org/message-id/1909358.1767854695%40sss.pgh.pa.us https://www.postgresql.org/message-id/7k27ut6kugt2mizo5cy5wplbbrz4ccbkxvsc2iqu5yde344iya%40dxktdjw6u... I've pushed v4. -- John Naylor Amazon Web Services ^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Correct comment wording in extension.c 2026-01-13 05:40 Re: Correct comment wording in extension.c John Naylor <[email protected]> @ 2026-01-13 06:31 ` Chao Li <[email protected]> 0 siblings, 0 replies; 3+ messages in thread From: Chao Li @ 2026-01-13 06:31 UTC (permalink / raw) To: John Naylor <[email protected]>; +Cc: li carol <[email protected]>; albert tan <[email protected]>; [email protected] <[email protected]> > On Jan 13, 2026, at 13:40, John Naylor <[email protected]> wrote: > > On Sun, Jan 11, 2026 at 11:58 AM Chao Li <[email protected]> wrote: >> v4-0001 looks good to me. > > When I say I'm going to commit "unless/barring", no response is > necessary unless there is a problem. > >> I just went through extension.c and got a few more comment improvements. I put them in v5-0002, please take a look. > > - * for them therefore uses about O(N^2) time when there are N versions of > + * for them therefore uses O(N^2) time when there are N versions of > > - /* store the OID of the namespace to-be-changed */ > + /* store the OID of the namespace to be changed */ > > Please read these responses to you from last week: > > https://www.postgresql.org/message-id/1909358.1767854695%40sss.pgh.pa.us > https://www.postgresql.org/message-id/7k27ut6kugt2mizo5cy5wplbbrz4ccbkxvsc2iqu5yde344iya%40dxktdjw6u... > > I've pushed v4. > Sure, I have read them carefully. But you really missed: ``` diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c index 596105ee078..a9529692ae3 100644 --- a/src/backend/commands/extension.c +++ b/src/backend/commands/extension.c @@ -2398,7 +2398,7 @@ pg_available_extension_versions(PG_FUNCTION_ARGS) /* * Ignore already-found names. They are not reachable by the - * path search, so don't shown them. + * path search, so don't show them. */ extname_str = makeString(extname); if (list_member(found_ext, extname_str)) ``` This is not the one in v4. Best regards, -- Chao Li (Evan) HighGo Software Co., Ltd. https://www.highgo.com/ ^ permalink raw reply [nested|flat] 3+ messages in thread
end of thread, other threads:[~2026-01-13 06:31 UTC | newest] Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2020-09-12 13:07 [PATCH 8/8] Ignore correlation for new BRIN opclasses Tomas Vondra <[email protected]> 2026-01-13 05:40 Re: Correct comment wording in extension.c John Naylor <[email protected]> 2026-01-13 06:31 ` Re: Correct comment wording in extension.c Chao Li <[email protected]>
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