From df3f5dfd194a837dc430c3a70bfc527b979935b3 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 14 Jul 2002 21:08:08 +0000
Subject: [PATCH] In DeleteAttributeTuples, use a single indexscan instead of
the multiple scans that will most likely be caused by SearchSysCache probes.
Also, share some code between index deletion and table deletion.
---
src/backend/catalog/heap.c | 337 ++++++++++++++++++------------------
src/backend/catalog/index.c | 45 +----
src/include/catalog/heap.h | 5 +-
3 files changed, 181 insertions(+), 206 deletions(-)
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 207090ae70a..48f7cae1aa0 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.205 2002/07/12 18:43:13 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.206 2002/07/14 21:08:08 tgl Exp $
*
*
* INTERFACE ROUTINES
@@ -66,13 +66,11 @@ static void AddNewRelationTuple(Relation pg_class_desc,
Relation new_rel_desc,
Oid new_rel_oid, Oid new_type_oid,
char relkind, bool relhasoids);
-static void DeleteAttributeTuples(Relation rel);
-static void DeleteRelationTuple(Relation rel);
-static void RelationRemoveInheritance(Relation relation);
static void AddNewRelationType(const char *typeName,
Oid typeNamespace,
Oid new_rel_oid,
Oid new_type_oid);
+static void RelationRemoveInheritance(Relation relation);
static void StoreAttrDefault(Relation rel, AttrNumber attnum, char *adbin);
static void StoreRelCheck(Relation rel, char *ccname, char *ccbin);
static void StoreConstraints(Relation rel, TupleDesc tupdesc);
@@ -793,193 +791,72 @@ RelationRemoveInheritance(Relation relation)
/*
* DeleteRelationTuple
+ *
+ * Remove pg_class row for the given relid.
+ *
+ * Note: this is shared by relation deletion and index deletion. It's
+ * not intended for use anyplace else.
*/
-static void
-DeleteRelationTuple(Relation rel)
+void
+DeleteRelationTuple(Oid relid)
{
Relation pg_class_desc;
HeapTuple tup;
- /*
- * open pg_class
- */
+ /* Grab an appropriate lock on the pg_class relation */
pg_class_desc = heap_openr(RelationRelationName, RowExclusiveLock);
- tup = SearchSysCacheCopy(RELOID,
- ObjectIdGetDatum(rel->rd_id),
- 0, 0, 0);
+ tup = SearchSysCache(RELOID,
+ ObjectIdGetDatum(relid),
+ 0, 0, 0);
if (!HeapTupleIsValid(tup))
- elog(ERROR, "Relation \"%s\" does not exist",
- RelationGetRelationName(rel));
+ elog(ERROR, "DeleteRelationTuple: cache lookup failed for relation %u",
+ relid);
- /*
- * delete the relation tuple from pg_class, and finish up.
- */
+ /* delete the relation tuple from pg_class, and finish up */
simple_heap_delete(pg_class_desc, &tup->t_self);
- heap_freetuple(tup);
- heap_close(pg_class_desc, RowExclusiveLock);
-}
+ ReleaseSysCache(tup);
-/* --------------------------------
- * RelationTruncateIndexes - This routine is used to truncate all
- * indices associated with the heap relation to zero tuples.
- * The routine will truncate and then reconstruct the indices on
- * the relation specified by the heapId parameter.
- * --------------------------------
- */
-static void
-RelationTruncateIndexes(Oid heapId)
-{
- Relation indexRelation;
- ScanKeyData entry;
- SysScanDesc scan;
- HeapTuple indexTuple;
-
- /* Scan pg_index to find indexes on specified heap */
- indexRelation = heap_openr(IndexRelationName, AccessShareLock);
- ScanKeyEntryInitialize(&entry, 0,
- Anum_pg_index_indrelid,
- F_OIDEQ,
- ObjectIdGetDatum(heapId));
- scan = systable_beginscan(indexRelation, IndexIndrelidIndex, true,
- SnapshotNow, 1, &entry);
-
- while (HeapTupleIsValid(indexTuple = systable_getnext(scan)))
- {
- Form_pg_index indexform = (Form_pg_index) GETSTRUCT(indexTuple);
- Oid indexId;
- IndexInfo *indexInfo;
- Relation heapRelation,
- currentIndex;
-
- /*
- * For each index, fetch info needed for index_build
- */
- indexId = indexform->indexrelid;
- indexInfo = BuildIndexInfo(indexform);
-
- /*
- * We have to re-open the heap rel each time through this loop
- * because index_build will close it again. We need grab no lock,
- * however, because we assume heap_truncate is holding an
- * exclusive lock on the heap rel.
- */
- heapRelation = heap_open(heapId, NoLock);
-
- /* Open the index relation */
- currentIndex = index_open(indexId);
-
- /* Obtain exclusive lock on it, just to be sure */
- LockRelation(currentIndex, AccessExclusiveLock);
-
- /*
- * Drop any buffers associated with this index. If they're dirty,
- * they're just dropped without bothering to flush to disk.
- */
- DropRelationBuffers(currentIndex);
-
- /* Now truncate the actual data and set blocks to zero */
- smgrtruncate(DEFAULT_SMGR, currentIndex, 0);
- currentIndex->rd_nblocks = 0;
- currentIndex->rd_targblock = InvalidBlockNumber;
-
- /* Initialize the index and rebuild */
- index_build(heapRelation, currentIndex, indexInfo);
-
- /*
- * index_build will close both the heap and index relations (but
- * not give up the locks we hold on them).
- */
- }
-
- /* Complete the scan and close pg_index */
- systable_endscan(scan);
- heap_close(indexRelation, AccessShareLock);
+ heap_close(pg_class_desc, RowExclusiveLock);
}
-/* ----------------------------
- * heap_truncate
+/*
+ * DeleteAttributeTuples
*
- * This routine is used to truncate the data from the
- * storage manager of any data within the relation handed
- * to this routine.
- * ----------------------------
+ * Remove pg_attribute rows for the given relid.
+ *
+ * Note: this is shared by relation deletion and index deletion. It's
+ * not intended for use anyplace else.
*/
-
void
-heap_truncate(Oid rid)
+DeleteAttributeTuples(Oid relid)
{
- Relation rel;
-
- /* Open relation for processing, and grab exclusive access on it. */
-
- rel = heap_open(rid, AccessExclusiveLock);
-
- /*
- * TRUNCATE TABLE within a transaction block is dangerous, because if
- * the transaction is later rolled back we have no way to undo
- * truncation of the relation's physical file. Disallow it except for
- * a rel created in the current xact (which would be deleted on abort,
- * anyway).
- */
- if (IsTransactionBlock() && !rel->rd_myxactonly)
- elog(ERROR, "TRUNCATE TABLE cannot run inside a transaction block");
-
- /*
- * Release any buffers associated with this relation. If they're
- * dirty, they're just dropped without bothering to flush to disk.
- */
- DropRelationBuffers(rel);
-
- /* Now truncate the actual data and set blocks to zero */
- smgrtruncate(DEFAULT_SMGR, rel, 0);
- rel->rd_nblocks = 0;
- rel->rd_targblock = InvalidBlockNumber;
-
- /* If this relation has indexes, truncate the indexes too */
- RelationTruncateIndexes(rid);
-
- /*
- * Close the relation, but keep exclusive lock on it until commit.
- */
- heap_close(rel, NoLock);
-}
+ Relation attrel;
+ SysScanDesc scan;
+ ScanKeyData key[1];
+ HeapTuple atttup;
+ /* Grab an appropriate lock on the pg_attribute relation */
+ attrel = heap_openr(AttributeRelationName, RowExclusiveLock);
-/* --------------------------------
- * DeleteAttributeTuples
- *
- * --------------------------------
- */
-static void
-DeleteAttributeTuples(Relation rel)
-{
- Relation pg_attribute_desc;
- HeapTuple tup;
- int2 attnum;
+ /* Use the index to scan only attributes of the target relation */
+ ScanKeyEntryInitialize(&key[0], 0x0,
+ Anum_pg_attribute_attrelid, F_OIDEQ,
+ ObjectIdGetDatum(relid));
- /*
- * open pg_attribute
- */
- pg_attribute_desc = heap_openr(AttributeRelationName, RowExclusiveLock);
+ scan = systable_beginscan(attrel, AttributeRelidNumIndex, true,
+ SnapshotNow, 1, key);
- for (attnum = FirstLowInvalidHeapAttributeNumber + 1;
- attnum <= rel->rd_att->natts;
- attnum++)
+ /* Delete all the matching tuples */
+ while ((atttup = systable_getnext(scan)) != NULL)
{
- tup = SearchSysCacheCopy(ATTNUM,
- ObjectIdGetDatum(RelationGetRelid(rel)),
- Int16GetDatum(attnum),
- 0, 0);
- if (HeapTupleIsValid(tup))
- {
- simple_heap_delete(pg_attribute_desc, &tup->t_self);
- heap_freetuple(tup);
- }
+ simple_heap_delete(attrel, &atttup->t_self);
}
- heap_close(pg_attribute_desc, RowExclusiveLock);
+ /* Clean up after the scan */
+ systable_endscan(scan);
+ heap_close(attrel, RowExclusiveLock);
}
/* ----------------------------------------------------------------
@@ -1033,14 +910,14 @@ heap_drop_with_catalog(Oid rid)
/*
* delete attribute tuples and associated defaults
*/
- DeleteAttributeTuples(rel);
+ DeleteAttributeTuples(RelationGetRelid(rel));
RemoveDefaults(rel);
/*
* delete relation tuple
*/
- DeleteRelationTuple(rel);
+ DeleteRelationTuple(RelationGetRelid(rel));
/*
* unlink the relation's physical file and finish up.
@@ -1734,3 +1611,127 @@ RemoveStatistics(Relation rel)
heap_endscan(scan);
heap_close(pgstatistic, RowExclusiveLock);
}
+
+
+/*
+ * RelationTruncateIndexes - truncate all
+ * indices associated with the heap relation to zero tuples.
+ *
+ * The routine will truncate and then reconstruct the indices on
+ * the relation specified by the heapId parameter.
+ */
+static void
+RelationTruncateIndexes(Oid heapId)
+{
+ Relation indexRelation;
+ ScanKeyData entry;
+ SysScanDesc scan;
+ HeapTuple indexTuple;
+
+ /* Scan pg_index to find indexes on specified heap */
+ indexRelation = heap_openr(IndexRelationName, AccessShareLock);
+ ScanKeyEntryInitialize(&entry, 0,
+ Anum_pg_index_indrelid,
+ F_OIDEQ,
+ ObjectIdGetDatum(heapId));
+ scan = systable_beginscan(indexRelation, IndexIndrelidIndex, true,
+ SnapshotNow, 1, &entry);
+
+ while (HeapTupleIsValid(indexTuple = systable_getnext(scan)))
+ {
+ Form_pg_index indexform = (Form_pg_index) GETSTRUCT(indexTuple);
+ Oid indexId;
+ IndexInfo *indexInfo;
+ Relation heapRelation,
+ currentIndex;
+
+ /*
+ * For each index, fetch info needed for index_build
+ */
+ indexId = indexform->indexrelid;
+ indexInfo = BuildIndexInfo(indexform);
+
+ /*
+ * We have to re-open the heap rel each time through this loop
+ * because index_build will close it again. We need grab no lock,
+ * however, because we assume heap_truncate is holding an
+ * exclusive lock on the heap rel.
+ */
+ heapRelation = heap_open(heapId, NoLock);
+
+ /* Open the index relation */
+ currentIndex = index_open(indexId);
+
+ /* Obtain exclusive lock on it, just to be sure */
+ LockRelation(currentIndex, AccessExclusiveLock);
+
+ /*
+ * Drop any buffers associated with this index. If they're dirty,
+ * they're just dropped without bothering to flush to disk.
+ */
+ DropRelationBuffers(currentIndex);
+
+ /* Now truncate the actual data and set blocks to zero */
+ smgrtruncate(DEFAULT_SMGR, currentIndex, 0);
+ currentIndex->rd_nblocks = 0;
+ currentIndex->rd_targblock = InvalidBlockNumber;
+
+ /* Initialize the index and rebuild */
+ index_build(heapRelation, currentIndex, indexInfo);
+
+ /*
+ * index_build will close both the heap and index relations (but
+ * not give up the locks we hold on them).
+ */
+ }
+
+ /* Complete the scan and close pg_index */
+ systable_endscan(scan);
+ heap_close(indexRelation, AccessShareLock);
+}
+
+/*
+ * heap_truncate
+ *
+ * This routine is used to truncate the data from the
+ * storage manager of any data within the relation handed
+ * to this routine.
+ */
+void
+heap_truncate(Oid rid)
+{
+ Relation rel;
+
+ /* Open relation for processing, and grab exclusive access on it. */
+
+ rel = heap_open(rid, AccessExclusiveLock);
+
+ /*
+ * TRUNCATE TABLE within a transaction block is dangerous, because if
+ * the transaction is later rolled back we have no way to undo
+ * truncation of the relation's physical file. Disallow it except for
+ * a rel created in the current xact (which would be deleted on abort,
+ * anyway).
+ */
+ if (IsTransactionBlock() && !rel->rd_myxactonly)
+ elog(ERROR, "TRUNCATE TABLE cannot run inside a transaction block");
+
+ /*
+ * Release any buffers associated with this relation. If they're
+ * dirty, they're just dropped without bothering to flush to disk.
+ */
+ DropRelationBuffers(rel);
+
+ /* Now truncate the actual data and set blocks to zero */
+ smgrtruncate(DEFAULT_SMGR, rel, 0);
+ rel->rd_nblocks = 0;
+ rel->rd_targblock = InvalidBlockNumber;
+
+ /* If this relation has indexes, truncate the indexes too */
+ RelationTruncateIndexes(rid);
+
+ /*
+ * Close the relation, but keep exclusive lock on it until commit.
+ */
+ heap_close(rel, NoLock);
+}
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 30cef89feff..996fb80a7cb 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.182 2002/07/12 18:43:13 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.183 2002/07/14 21:08:08 tgl Exp $
*
*
* INTERFACE ROUTINES
@@ -789,10 +789,7 @@ index_drop(Oid indexId)
Relation userHeapRelation;
Relation userIndexRelation;
Relation indexRelation;
- Relation relationRelation;
- Relation attributeRelation;
HeapTuple tuple;
- int16 attnum;
int i;
Assert(OidIsValid(indexId));
@@ -818,53 +815,27 @@ index_drop(Oid indexId)
/*
* fix RELATION relation
*/
- relationRelation = heap_openr(RelationRelationName, RowExclusiveLock);
-
- /* Remove the pg_class tuple for the index itself */
- tuple = SearchSysCacheCopy(RELOID,
- ObjectIdGetDatum(indexId),
- 0, 0, 0);
- if (!HeapTupleIsValid(tuple))
- elog(ERROR, "index_drop: cache lookup failed for index %u",
- indexId);
-
- simple_heap_delete(relationRelation, &tuple->t_self);
- heap_freetuple(tuple);
-
- heap_close(relationRelation, RowExclusiveLock);
-
+ DeleteRelationTuple(indexId);
/*
* fix ATTRIBUTE relation
*/
- attributeRelation = heap_openr(AttributeRelationName, RowExclusiveLock);
-
- attnum = 1; /* indexes start at 1 */
-
- while (HeapTupleIsValid(tuple = SearchSysCacheCopy(ATTNUM,
- ObjectIdGetDatum(indexId),
- Int16GetDatum(attnum),
- 0, 0)))
- {
- simple_heap_delete(attributeRelation, &tuple->t_self);
- heap_freetuple(tuple);
- attnum++;
- }
- heap_close(attributeRelation, RowExclusiveLock);
+ DeleteAttributeTuples(indexId);
/*
* fix INDEX relation
*/
indexRelation = heap_openr(IndexRelationName, RowExclusiveLock);
- tuple = SearchSysCacheCopy(INDEXRELID,
- ObjectIdGetDatum(indexId),
- 0, 0, 0);
+ tuple = SearchSysCache(INDEXRELID,
+ ObjectIdGetDatum(indexId),
+ 0, 0, 0);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "index_drop: cache lookup failed for index %u",
indexId);
simple_heap_delete(indexRelation, &tuple->t_self);
- heap_freetuple(tuple);
+
+ ReleaseSysCache(tuple);
heap_close(indexRelation, RowExclusiveLock);
/*
diff --git a/src/include/catalog/heap.h b/src/include/catalog/heap.h
index 5cf87e2631f..44c8e13bf61 100644
--- a/src/include/catalog/heap.h
+++ b/src/include/catalog/heap.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: heap.h,v 1.52 2002/07/12 18:43:19 tgl Exp $
+ * $Id: heap.h,v 1.53 2002/07/14 21:08:08 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -61,6 +61,9 @@ extern Node *cookDefault(ParseState *pstate,
extern int RemoveRelConstraints(Relation rel, const char *constrName,
DropBehavior behavior);
+extern void DeleteRelationTuple(Oid relid);
+extern void DeleteAttributeTuples(Oid relid);
+
extern Form_pg_attribute SystemAttributeDefinition(AttrNumber attno,
bool relhasoids);
--
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