get_constraint_index() does its work by going through pg_depend. It was
added before pg_constraint.conindid was added, and some callers are
still not changed. Are there reasons for that? Probably not. The
attached patch changes get_constraint_index() to an lsyscache-style
lookup instead.
The nearby get_index_constraint() should probably also be changed to
scan pg_constraint instead of pg_depend, but that doesn't have a
syscache to use, so it would be a different approach, so I figured I'd
ask about get_constraint_index() first.
From 29371949b2e61f894f651eef990c3c6eabfa8145 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Mon, 7 Dec 2020 10:38:36 +0100
Subject: [PATCH] Change get_constraint_index() to use pg_constraint.conindid
It was still using a scan of pg_depend instead of using the conindid
column that has been added since.
---
src/backend/catalog/pg_depend.c | 69 ----------------------------
src/backend/commands/tablecmds.c | 1 -
src/backend/optimizer/util/plancat.c | 1 -
src/backend/utils/adt/ruleutils.c | 3 +-
src/backend/utils/cache/lsyscache.c | 27 +++++++++++
src/include/catalog/dependency.h | 2 -
src/include/utils/lsyscache.h | 1 +
7 files changed, 29 insertions(+), 75 deletions(-)
diff --git a/src/backend/catalog/pg_depend.c b/src/backend/catalog/pg_depend.c
index 25290c821f..429791694f 100644
--- a/src/backend/catalog/pg_depend.c
+++ b/src/backend/catalog/pg_depend.c
@@ -968,75 +968,6 @@ getIdentitySequence(Oid relid, AttrNumber attnum, bool
missing_ok)
return linitial_oid(seqlist);
}
-/*
- * get_constraint_index
- * Given the OID of a unique, primary-key, or exclusion constraint,
- * return the OID of the underlying index.
- *
- * Return InvalidOid if the index couldn't be found; this suggests the
- * given OID is bogus, but we leave it to caller to decide what to do.
- */
-Oid
-get_constraint_index(Oid constraintId)
-{
- Oid indexId = InvalidOid;
- Relation depRel;
- ScanKeyData key[3];
- SysScanDesc scan;
- HeapTuple tup;
-
- /* Search the dependency table for the dependent index */
- depRel = table_open(DependRelationId, AccessShareLock);
-
- ScanKeyInit(&key[0],
- Anum_pg_depend_refclassid,
- BTEqualStrategyNumber, F_OIDEQ,
- ObjectIdGetDatum(ConstraintRelationId));
- ScanKeyInit(&key[1],
- Anum_pg_depend_refobjid,
- BTEqualStrategyNumber, F_OIDEQ,
- ObjectIdGetDatum(constraintId));
- ScanKeyInit(&key[2],
- Anum_pg_depend_refobjsubid,
- BTEqualStrategyNumber, F_INT4EQ,
- Int32GetDatum(0));
-
- scan = systable_beginscan(depRel, DependReferenceIndexId, true,
- NULL, 3, key);
-
- while (HeapTupleIsValid(tup = systable_getnext(scan)))
- {
- Form_pg_depend deprec = (Form_pg_depend) GETSTRUCT(tup);
-
- /*
- * We assume any internal dependency of an index on the
constraint
- * must be what we are looking for.
- */
- if (deprec->classid == RelationRelationId &&
- deprec->objsubid == 0 &&
- deprec->deptype == DEPENDENCY_INTERNAL)
- {
- char relkind =
get_rel_relkind(deprec->objid);
-
- /*
- * This is pure paranoia; there shouldn't be any other
relkinds
- * dependent on a constraint.
- */
- if (relkind != RELKIND_INDEX &&
- relkind != RELKIND_PARTITIONED_INDEX)
- continue;
-
- indexId = deprec->objid;
- break;
- }
- }
-
- systable_endscan(scan);
- table_close(depRel, AccessShareLock);
-
- return indexId;
-}
-
/*
* get_index_constraint
* Given the OID of an index, return the OID of the owning unique,
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 46f1637e77..1fa9f19f08 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -26,7 +26,6 @@
#include "access/xact.h"
#include "access/xlog.h"
#include "catalog/catalog.h"
-#include "catalog/dependency.h"
#include "catalog/heap.h"
#include "catalog/index.h"
#include "catalog/namespace.h"
diff --git a/src/backend/optimizer/util/plancat.c
b/src/backend/optimizer/util/plancat.c
index 3e94256d34..daf1759623 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -26,7 +26,6 @@
#include "access/transam.h"
#include "access/xlog.h"
#include "catalog/catalog.h"
-#include "catalog/dependency.h"
#include "catalog/heap.h"
#include "catalog/index.h"
#include "catalog/pg_am.h"
diff --git a/src/backend/utils/adt/ruleutils.c
b/src/backend/utils/adt/ruleutils.c
index c2c6df2a4f..ad582f99a5 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -24,7 +24,6 @@
#include "access/relation.h"
#include "access/sysattr.h"
#include "access/table.h"
-#include "catalog/dependency.h"
#include "catalog/pg_aggregate.h"
#include "catalog/pg_am.h"
#include "catalog/pg_authid.h"
@@ -2140,7 +2139,7 @@ pg_get_constraintdef_worker(Oid constraintId, bool
fullCommand,
appendStringInfoChar(&buf, ')');
- indexId = get_constraint_index(constraintId);
+ indexId = conForm->conindid;
/* Build including column list (from
pg_index.indkeys) */
indtup = SearchSysCache1(INDEXRELID,
ObjectIdGetDatum(indexId));
diff --git a/src/backend/utils/cache/lsyscache.c
b/src/backend/utils/cache/lsyscache.c
index ae23299162..47a8365849 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -1094,6 +1094,33 @@ get_constraint_name(Oid conoid)
return NULL;
}
+/*
+ * get_constraint_index
+ * Given the OID of a unique, primary-key, or exclusion constraint,
+ * return the OID of the underlying index.
+ *
+ * Return InvalidOid if the index couldn't be found; this suggests the
+ * given OID is bogus, but we leave it to caller to decide what to do.
+ */
+Oid
+get_constraint_index(Oid conoid)
+{
+ HeapTuple tp;
+
+ tp = SearchSysCache1(CONSTROID, ObjectIdGetDatum(conoid));
+ if (HeapTupleIsValid(tp))
+ {
+ Form_pg_constraint contup = (Form_pg_constraint) GETSTRUCT(tp);
+ Oid result;
+
+ result = contup->conindid;
+ ReleaseSysCache(tp);
+ return result;
+ }
+ else
+ return InvalidOid;
+}
+
/* ---------- LANGUAGE CACHE ----------
*/
char *
diff --git a/src/include/catalog/dependency.h b/src/include/catalog/dependency.h
index 901d5019cd..1fcc4a39ec 100644
--- a/src/include/catalog/dependency.h
+++ b/src/include/catalog/dependency.h
@@ -235,8 +235,6 @@ extern bool sequenceIsOwned(Oid seqId, char deptype, Oid
*tableId, int32 *colId)
extern List *getOwnedSequences(Oid relid);
extern Oid getIdentitySequence(Oid relid, AttrNumber attnum, bool
missing_ok);
-extern Oid get_constraint_index(Oid constraintId);
-
extern Oid get_index_constraint(Oid indexId);
extern List *get_index_ref_constraints(Oid indexId);
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index fecfe1f4f6..c97e12dde8 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -96,6 +96,7 @@ extern Oid get_cast_oid(Oid sourcetypeid, Oid
targettypeid, bool missing_ok);
extern char *get_collation_name(Oid colloid);
extern bool get_collation_isdeterministic(Oid colloid);
extern char *get_constraint_name(Oid conoid);
+extern Oid get_constraint_index(Oid conoid);
extern char *get_language_name(Oid langoid, bool missing_ok);
extern Oid get_opclass_family(Oid opclass);
extern Oid get_opclass_input_type(Oid opclass);
--
2.29.2
