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Fix performance problems with pg_index lookups (see, for example,
discussion of 5/19/00). pg_index is now searched for indexes of a relation using an indexscan. Moreover, this is done once and cached in the relcache entry for the relation, in the form of a list of OIDs for the indexes. This list is used by the parser and executor to drive lookups in the pg_index syscache when they want to know the properties of the indexes. Net result: index information will be fully cached for repetitive operations such as inserts.
1 parent 9cf80f2 commit d03a933

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13 files changed

+384
-520
lines changed

13 files changed

+384
-520
lines changed

‎src/backend/catalog/index.c

Lines changed: 29 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.116 2000/06/17 04:56:36 tgl Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.117 2000/06/17 21:48:39 tgl Exp $
1212
*
1313
*
1414
* INTERFACE ROUTINES
@@ -1105,6 +1105,7 @@ index_create(char *heapRelationName,
11051105
void
11061106
index_drop(Oid indexId)
11071107
{
1108+
Oid heapId;
11081109
Relation userHeapRelation;
11091110
Relation userIndexRelation;
11101111
Relation indexRelation;
@@ -1125,8 +1126,8 @@ index_drop(Oid indexId)
11251126
* else other backends will still see this index in pg_index.
11261127
* ----------------
11271128
*/
1128-
userHeapRelation = heap_open(IndexGetRelation(indexId),
1129-
AccessExclusiveLock);
1129+
heapId = IndexGetRelation(indexId);
1130+
userHeapRelation = heap_open(heapId, AccessExclusiveLock);
11301131

11311132
userIndexRelation = index_open(indexId);
11321133
LockRelation(userIndexRelation, AccessExclusiveLock);
@@ -1158,6 +1159,7 @@ index_drop(Oid indexId)
11581159
*/
11591160
relationRelation = heap_openr(RelationRelationName, RowExclusiveLock);
11601161

1162+
/* Remove the pg_class tuple for the index itself */
11611163
tuple = SearchSysCacheTupleCopy(RELOID,
11621164
ObjectIdGetDatum(indexId),
11631165
0, 0, 0);
@@ -1166,6 +1168,23 @@ index_drop(Oid indexId)
11661168

11671169
heap_delete(relationRelation, &tuple->t_self, NULL);
11681170
heap_freetuple(tuple);
1171+
1172+
/*
1173+
* Find the pg_class tuple for the owning relation. We do not attempt
1174+
* to clear relhasindex, since we are too lazy to test whether any other
1175+
* indexes remain (the next VACUUM will fix it if necessary). But we
1176+
* must send out a shared-cache-inval notice on the owning relation
1177+
* to ensure other backends update their relcache lists of indexes.
1178+
*/
1179+
tuple = SearchSysCacheTupleCopy(RELOID,
1180+
ObjectIdGetDatum(heapId),
1181+
0, 0, 0);
1182+
1183+
Assert(HeapTupleIsValid(tuple));
1184+
1185+
ImmediateInvalidateSharedHeapTuple(relationRelation, tuple);
1186+
heap_freetuple(tuple);
1187+
11691188
heap_close(relationRelation, RowExclusiveLock);
11701189

11711190
/* ----------------
@@ -1447,9 +1466,6 @@ setRelhasindexInplace(Oid relid, bool hasindex, bool immediate)
14471466
*/
14481467
if (pg_class_scan)
14491468
{
1450-
1451-
if (!IsBootstrapProcessingMode())
1452-
ImmediateInvalidateSharedHeapTuple(pg_class, tuple);
14531469
rd_rel = (Form_pg_class) GETSTRUCT(tuple);
14541470
rd_rel->relhasindex = hasindex;
14551471
WriteNoReleaseBuffer(pg_class_scan->rs_cbuf);
@@ -1461,12 +1477,18 @@ setRelhasindexInplace(Oid relid, bool hasindex, bool immediate)
14611477

14621478
htup.t_self = tuple->t_self;
14631479
heap_fetch(pg_class, SnapshotNow, &htup, &buffer);
1464-
ImmediateInvalidateSharedHeapTuple(pg_class, tuple);
14651480
rd_rel = (Form_pg_class) GETSTRUCT(&htup);
14661481
rd_rel->relhasindex = hasindex;
14671482
WriteBuffer(buffer);
14681483
}
14691484

1485+
/*
1486+
* Send out a shared-cache-inval message so other backends notice the
1487+
* update and fix their syscaches/relcaches.
1488+
*/
1489+
if (!IsBootstrapProcessingMode())
1490+
ImmediateInvalidateSharedHeapTuple(pg_class, tuple);
1491+
14701492
if (!pg_class_scan)
14711493
heap_freetuple(tuple);
14721494
else

‎src/backend/commands/copy.c

Lines changed: 24 additions & 58 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
*
88
*
99
* IDENTIFICATION
10-
* $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.114 2000/06/15 03:32:07 momjian Exp $
10+
* $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.115 2000/06/17 21:48:42 tgl Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -32,6 +32,7 @@
3232
#include "tcop/tcopprot.h"
3333
#include "utils/acl.h"
3434
#include "utils/builtins.h"
35+
#include "utils/relcache.h"
3536
#include "utils/syscache.h"
3637

3738
#ifdef MULTIBYTE
@@ -1081,78 +1082,43 @@ IsTypeByVal(Oid type)
10811082
* Space for the array itself is palloc'ed.
10821083
*/
10831084

1084-
typedef struct rel_list
1085-
{
1086-
Oid index_rel_oid;
1087-
struct rel_list *next;
1088-
} RelationList;
1089-
10901085
static void
10911086
GetIndexRelations(Oid main_relation_oid,
10921087
int *n_indices,
10931088
Relation **index_rels)
10941089
{
1095-
RelationList *head,
1096-
*scan;
1097-
Relation pg_index_rel;
1098-
HeapScanDesc scandesc;
1099-
Oid index_relation_oid;
1100-
HeapTuple tuple;
1101-
TupleDesc tupDesc;
1090+
Relation relation;
1091+
List *indexoidlist,
1092+
*indexoidscan;
11021093
int i;
1103-
bool isnull;
11041094

1105-
pg_index_rel = heap_openr(IndexRelationName, AccessShareLock);
1106-
scandesc = heap_beginscan(pg_index_rel, 0, SnapshotNow, 0, NULL);
1107-
tupDesc = RelationGetDescr(pg_index_rel);
1095+
relation = heap_open(main_relation_oid, AccessShareLock);
1096+
indexoidlist = RelationGetIndexList(relation);
11081097

1109-
*n_indices = 0;
1098+
*n_indices = length(indexoidlist);
11101099

1111-
head = (RelationList *) palloc(sizeof(RelationList));
1112-
scan = head;
1113-
head->next = NULL;
1100+
if (*n_indices > 0)
1101+
*index_rels = (Relation *) palloc(*n_indices * sizeof(Relation));
1102+
else
1103+
*index_rels = NULL;
11141104

1115-
while (HeapTupleIsValid(tuple = heap_getnext(scandesc, 0)))
1105+
i = 0;
1106+
foreach(indexoidscan, indexoidlist)
11161107
{
1108+
Oid indexoid = lfirsti(indexoidscan);
1109+
Relation index = index_open(indexoid);
11171110

1118-
index_relation_oid = (Oid) DatumGetInt32(heap_getattr(tuple, 2,
1119-
tupDesc, &isnull));
1120-
if (index_relation_oid == main_relation_oid)
1121-
{
1122-
scan->index_rel_oid = (Oid) DatumGetInt32(heap_getattr(tuple,
1123-
Anum_pg_index_indexrelid,
1124-
tupDesc, &isnull));
1125-
(*n_indices)++;
1126-
scan->next = (RelationList *) palloc(sizeof(RelationList));
1127-
scan = scan->next;
1128-
}
1129-
}
1130-
1131-
heap_endscan(scandesc);
1132-
heap_close(pg_index_rel, AccessShareLock);
1133-
1134-
/* We cannot trust to relhasindex of the main_relation now, so... */
1135-
if (*n_indices == 0)
1136-
return;
1137-
1138-
*index_rels = (Relation *) palloc(*n_indices * sizeof(Relation));
1139-
1140-
for (i = 0, scan = head; i < *n_indices; i++, scan = scan->next)
1141-
{
1142-
(*index_rels)[i] = index_open(scan->index_rel_oid);
11431111
/* see comments in ExecOpenIndices() in execUtils.c */
1144-
if ((*index_rels)[i] != NULL &&
1145-
((*index_rels)[i])->rd_rel->relam != BTREE_AM_OID &&
1146-
((*index_rels)[i])->rd_rel->relam != HASH_AM_OID)
1147-
LockRelation((*index_rels)[i], AccessExclusiveLock);
1112+
if (index != NULL &&
1113+
index->rd_rel->relam != BTREE_AM_OID &&
1114+
index->rd_rel->relam != HASH_AM_OID)
1115+
LockRelation(index, AccessExclusiveLock);
1116+
(*index_rels)[i] = index;
1117+
i++;
11481118
}
11491119

1150-
for (i = 0, scan = head; i < *n_indices + 1; i++)
1151-
{
1152-
scan = head->next;
1153-
pfree(head);
1154-
head = scan;
1155-
}
1120+
freeList(indexoidlist);
1121+
heap_close(relation, AccessShareLock);
11561122
}
11571123

11581124
/*

‎src/backend/commands/indexcmds.c

Lines changed: 8 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.29 2000/06/15 03:32:07 momjian Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.30 2000/06/17 21:48:42 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -221,6 +221,13 @@ DefineIndex(char *heapRelationName,
221221
lossy, unique, primary);
222222
}
223223

224+
/*
225+
* We update the relation's pg_class tuple even if it already has
226+
* relhasindex = true. This is needed to cause a shared-cache-inval
227+
* message to be sent for the pg_class tuple, which will cause other
228+
* backends to flush their relcache entries and in particular their
229+
* cached lists of the indexes for this relation.
230+
*/
224231
setRelhasindexInplace(relationId, true, false);
225232
}
226233

‎src/backend/commands/vacuum.c

Lines changed: 20 additions & 67 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.159 2000/05/29 17:40:43 momjian Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.160 2000/06/17 21:48:43 tgl Exp $
1212
*
1313
1414
*-------------------------------------------------------------------------
@@ -72,7 +72,7 @@ static void update_relstats(Oid relid, int num_pages, int num_tuples, bool hasin
7272
static VacPage tid_reaped(ItemPointer itemptr, VacPageList vacpagelist);
7373
static void reap_page(VacPageList vacpagelist, VacPage vacpage);
7474
static void vpage_insert(VacPageList vacpagelist, VacPage vpnew);
75-
static void get_indices(Oid relid, int *nindices, Relation **Irel);
75+
static void get_indices(Relation relation, int *nindices, Relation **Irel);
7676
static void close_indices(int nindices, Relation *Irel);
7777
static void get_index_desc(Relation onerel, int nindices, Relation *Irel, IndDesc **Idesc);
7878
static void *vac_find_eq(void *bot, int nelem, int size, void *elm,
@@ -416,7 +416,7 @@ vacuum_rel(Oid relid, bool analyze)
416416
/* Now open indices */
417417
nindices = 0;
418418
Irel = (Relation *) NULL;
419-
get_indices(vacrelstats->relid, &nindices, &Irel);
419+
get_indices(onerel, &nindices, &Irel);
420420
if (!Irel)
421421
reindex = false;
422422
else if (!RelationGetForm(onerel)->relhasindex)
@@ -2331,80 +2331,33 @@ CommonSpecialPortalIsOpen(void)
23312331
return CommonSpecialPortalInUse;
23322332
}
23332333

2334+
23342335
static void
2335-
get_indices(Oid relid, int *nindices, Relation **Irel)
2336+
get_indices(Relation relation, int *nindices, Relation **Irel)
23362337
{
2337-
Relation pgindex;
2338-
Relation irel;
2339-
TupleDesc tupdesc;
2340-
HeapTuple tuple;
2341-
HeapScanDesc scan;
2342-
Datum d;
2343-
int i,
2344-
k;
2345-
bool n;
2346-
ScanKeyData key;
2347-
Oid *ioid;
2348-
2349-
*nindices = i = 0;
2350-
2351-
ioid = (Oid *) palloc(10 * sizeof(Oid));
2352-
2353-
/* prepare a heap scan on the pg_index relation */
2354-
pgindex = heap_openr(IndexRelationName, AccessShareLock);
2355-
tupdesc = RelationGetDescr(pgindex);
2356-
2357-
ScanKeyEntryInitialize(&key, 0x0, Anum_pg_index_indrelid,
2358-
F_OIDEQ,
2359-
ObjectIdGetDatum(relid));
2360-
2361-
scan = heap_beginscan(pgindex, false, SnapshotNow, 1, &key);
2362-
2363-
while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
2364-
{
2365-
d = heap_getattr(tuple, Anum_pg_index_indexrelid,
2366-
tupdesc, &n);
2367-
i++;
2368-
if (i % 10 == 0)
2369-
ioid = (Oid *) repalloc(ioid, (i + 10) * sizeof(Oid));
2370-
ioid[i - 1] = DatumGetObjectId(d);
2371-
}
2338+
List *indexoidlist,
2339+
*indexoidscan;
2340+
int i;
23722341

2373-
heap_endscan(scan);
2374-
heap_close(pgindex, AccessShareLock);
2342+
indexoidlist = RelationGetIndexList(relation);
23752343

2376-
if (i == 0)
2377-
{ /* No one index found */
2378-
pfree(ioid);
2379-
return;
2380-
}
2344+
*nindices = length(indexoidlist);
23812345

2382-
if (Irel != (Relation **) NULL)
2383-
*Irel = (Relation *) palloc(i * sizeof(Relation));
2346+
if (*nindices > 0)
2347+
*Irel = (Relation *) palloc(*nindices * sizeof(Relation));
2348+
else
2349+
*Irel = NULL;
23842350

2385-
for (k = 0; i > 0;)
2351+
i = 0;
2352+
foreach(indexoidscan, indexoidlist)
23862353
{
2387-
irel = index_open(ioid[--i]);
2388-
if (irel != (Relation) NULL)
2389-
{
2390-
if (Irel != (Relation **) NULL)
2391-
(*Irel)[k] = irel;
2392-
else
2393-
index_close(irel);
2394-
k++;
2395-
}
2396-
else
2397-
elog(NOTICE, "CAN'T OPEN INDEX %u - SKIP IT", ioid[i]);
2398-
}
2399-
*nindices = k;
2400-
pfree(ioid);
2354+
Oid indexoid = lfirsti(indexoidscan);
24012355

2402-
if (Irel != (Relation **) NULL && *nindices == 0)
2403-
{
2404-
pfree(*Irel);
2405-
*Irel = (Relation *) NULL;
2356+
(*Irel)[i] = index_open(indexoid);
2357+
i++;
24062358
}
24072359

2360+
freeList(indexoidlist);
24082361
}
24092362

24102363

‎src/backend/executor/execMain.c

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -27,7 +27,7 @@
2727
*
2828
*
2929
* IDENTIFICATION
30-
* $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.117 2000/06/15 04:09:50 momjian Exp $
30+
* $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.118 2000/06/17 21:48:47 tgl Exp $
3131
*
3232
*-------------------------------------------------------------------------
3333
*/
@@ -735,7 +735,7 @@ InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
735735
*/
736736
if (resultRelationDesc->rd_rel->relhasindex &&
737737
operation != CMD_DELETE)
738-
ExecOpenIndices(resultRelationOid, resultRelationInfo);
738+
ExecOpenIndices(resultRelationInfo);
739739

740740
estate->es_result_relation_info = resultRelationInfo;
741741
}

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