public inbox for [email protected]  
help / color / mirror / Atom feed
[PATCH 9/9] Ignore correlation for new BRIN opclasses
3+ messages / 3 participants
[nested] [flat]

* [PATCH 9/9] 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 15a8258677..d2c4172f48 100644
--- a/src/backend/access/brin/brin_bloom.c
+++ b/src/backend/access/brin/brin_bloom.c
@@ -410,6 +410,7 @@ 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 02aa618b49..437efa8d31 100644
--- a/src/backend/access/brin/brin_minmax_multi.c
+++ b/src/backend/access/brin/brin_minmax_multi.c
@@ -1798,6 +1798,7 @@ 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 47ca4ddbb5..bf40f9ce32 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 fdaff42722..5fbf8cf9c7 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


--------------4B194FF8F3EA3786FF9EAE1F
Content-Type: text/x-patch; charset=UTF-8;
 name="0008-Define-multi-minmax-oclasses-for-types-with-20210203.patch"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
 filename*0="0008-Define-multi-minmax-oclasses-for-types-with-20210203.pa";
 filename*1="tch"



^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Standardize spelling of "power of two"
@ 2023-08-29 08:56 Kyotaro Horiguchi <[email protected]>
  2023-08-29 09:26 ` Re: Standardize spelling of "power of two" Daniel Gustafsson <[email protected]>
  0 siblings, 1 reply; 3+ messages in thread

From: Kyotaro Horiguchi @ 2023-08-29 08:56 UTC (permalink / raw)
  To: [email protected]

Hello.

pg_resetwal and initdb has an error message like this:

msgid "argument of --wal-segsize must be a power of 2 between 1 and 1024"

In other parts in the tree, however, we spell it as "power of two". I
think it would make sense to standardize the spelling for
consistency. See the attached.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center


Attachments:

  [text/x-patch] standardize_spelling_of_power_of_two.patch (1.1K, ../../[email protected]/2-standardize_spelling_of_power_of_two.patch)
  download | inline diff:
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index c66467eb95..905b979947 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -3350,7 +3350,7 @@ main(int argc, char *argv[])
 	check_need_password(authmethodlocal, authmethodhost);
 
 	if (!IsValidWalSegSize(wal_segment_size_mb * 1024 * 1024))
-		pg_fatal("argument of %s must be a power of 2 between 1 and 1024", "--wal-segsize");
+		pg_fatal("argument of %s must be a power of two between 1 and 1024", "--wal-segsize");
 
 	get_restricted_token();
 
diff --git a/src/bin/pg_resetwal/pg_resetwal.c b/src/bin/pg_resetwal/pg_resetwal.c
index 9bebc2a995..25ecdaaa15 100644
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -298,7 +298,7 @@ main(int argc, char *argv[])
 						exit(1);
 					set_wal_segsize = wal_segsize_mb * 1024 * 1024;
 					if (!IsValidWalSegSize(set_wal_segsize))
-						pg_fatal("argument of %s must be a power of 2 between 1 and 1024", "--wal-segsize");
+						pg_fatal("argument of %s must be a power of two between 1 and 1024", "--wal-segsize");
 					break;
 				}
 


^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: Standardize spelling of "power of two"
  2023-08-29 08:56 Standardize spelling of "power of two" Kyotaro Horiguchi <[email protected]>
@ 2023-08-29 09:26 ` Daniel Gustafsson <[email protected]>
  0 siblings, 0 replies; 3+ messages in thread

From: Daniel Gustafsson @ 2023-08-29 09:26 UTC (permalink / raw)
  To: Kyotaro Horiguchi <[email protected]>; +Cc: [email protected]

> On 29 Aug 2023, at 10:56, Kyotaro Horiguchi <[email protected]> wrote:

> pg_resetwal and initdb has an error message like this:
> 
> msgid "argument of --wal-segsize must be a power of 2 between 1 and 1024"
> 
> In other parts in the tree, however, we spell it as "power of two". I
> think it would make sense to standardize the spelling for
> consistency. See the attached.

Agreed.  While we have numerous "power of 2" these were the only ones in
translated user-facing messages, so I've pushed this to master (it didn't seem
worth disrupting translations for 16 as we are so close to wrapping it, if
others disagree I can backpatch).

--
Daniel Gustafsson







^ permalink  raw  reply  [nested|flat] 3+ messages in thread


end of thread, other threads:[~2023-08-29 09:26 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 9/9] Ignore correlation for new BRIN opclasses Tomas Vondra <[email protected]>
2023-08-29 08:56 Standardize spelling of "power of two" Kyotaro Horiguchi <[email protected]>
2023-08-29 09:26 ` Re: Standardize spelling of "power of two" Daniel Gustafsson <[email protected]>

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox