database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-27 12:41:57 +03:00
Code Activity

Revert "Use Foreign Key relationships to infer multi-column join selectivity".

Browse Source 
This commit reverts 137805f89 as well as the associated commits 015e88942,
5306df283, and 68d704edb.  We found multiple bugs in this feature, and
there was concern about possible planner slowdown (though to be fair,
exhibiting a very large slowdown proved difficult).  The way forward
requires a considerable rewrite, which may or may not be possible to
accomplish in time for beta2.  In my judgment reviewing the rewrite will
be easier to accomplish starting from a clean slate, so let's temporarily
revert what's there now.  This also leaves us in a safe state if it turns
out to be necessary to postpone the rewrite to the next development cycle.

Discussion: <20160429102531.GA13701@huehner.biz>
This commit is contained in:
Tom Lane
2016-06-07 17:21:17 -04:00
parent 5c6d2a5e7c
commit 77ba610805
12 changed files with 25 additions and 591 deletions
Download Patch File Download Diff File Expand all files Collapse all files

85
src/backend/optimizer/util/plancat.c
View File

@ -28,7 +28,6 @@
#include "catalog/dependency.h"
#include "catalog/heap.h"
#include "catalog/pg_am.h"
#include "catalog/pg_constraint.h"
#include "foreign/fdwapi.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
@ -42,7 +41,6 @@
#include "rewrite/rewriteManip.h"
#include "storage/bufmgr.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
#include "utils/rel.h"
#include "utils/snapmgr.h"
@ -96,9 +94,6 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
Relation relation;
bool hasindex;
List *indexinfos = NIL;
List *fkinfos = NIL;
List *fkoidlist;
ListCell *l;
/*
* We need not lock the relation since it was already locked, either by
@ -149,6 +144,7 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
if (hasindex)
{
List *indexoidlist;
ListCell *l;
LOCKMODE lmode;
indexoidlist = RelationGetIndexList(relation);
@ -395,85 +391,6 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
rel->indexlist = indexinfos;
/*
* Load foreign key data. Note this is the definitional data from the
* catalog only and does not lock the referenced tables here. The
* precise definition of the FK is important and may affect the usage
* elsewhere in the planner, e.g. if the constraint is deferred or
* if the constraint is not valid then relying upon this in the executor
* may not be accurate, though might be considered a useful estimate for
* planning purposes.
*/
fkoidlist = RelationGetFKeyList(relation);
foreach(l, fkoidlist)
{
Oid fkoid = lfirst_oid(l);
HeapTuple htup;
Form_pg_constraint constraint;
ForeignKeyOptInfo *info;
Datum adatum;
bool isnull;
ArrayType *arr;
int numkeys;
int i;
htup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(fkoid));
if (!HeapTupleIsValid(htup)) /* should not happen */
elog(ERROR, "cache lookup failed for constraint %u", fkoid);
constraint = (Form_pg_constraint) GETSTRUCT(htup);
Assert(constraint->contype == CONSTRAINT_FOREIGN);
info = makeNode(ForeignKeyOptInfo);
info->conrelid = constraint->conrelid;
info->confrelid = constraint->confrelid;
/* conkey */
adatum = SysCacheGetAttr(CONSTROID, htup,
Anum_pg_constraint_conkey, &isnull);
Assert(!isnull);
arr = DatumGetArrayTypeP(adatum);
numkeys = ARR_DIMS(arr)[0];
info->conkeys = (int*)palloc(numkeys * sizeof(int));
for (i = 0; i < numkeys; i++)
info->conkeys[i] = ((int16 *) ARR_DATA_PTR(arr))[i];
/* confkey */
adatum = SysCacheGetAttr(CONSTROID, htup,
Anum_pg_constraint_confkey, &isnull);
Assert(!isnull);
arr = DatumGetArrayTypeP(adatum);
Assert(numkeys == ARR_DIMS(arr)[0]);
info->confkeys = (int*)palloc(numkeys * sizeof(int));
for (i = 0; i < numkeys; i++)
info->confkeys[i] = ((int16 *) ARR_DATA_PTR(arr))[i];
/* conpfeqop */
adatum = SysCacheGetAttr(CONSTROID, htup,
Anum_pg_constraint_conpfeqop, &isnull);
Assert(!isnull);
arr = DatumGetArrayTypeP(adatum);
Assert(numkeys == ARR_DIMS(arr)[0]);
info->conpfeqop = (Oid*)palloc(numkeys * sizeof(Oid));
for (i = 0; i < numkeys; i++)
info->conpfeqop[i] = ((Oid *) ARR_DATA_PTR(arr))[i];
info->nkeys = numkeys;
ReleaseSysCache(htup);
fkinfos = lappend(fkinfos, info);
}
list_free(fkoidlist);
rel->fkeylist = fkinfos;
/* Grab foreign-table info using the relcache, while we have it */
if (relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
{