From: Teodor Sigaev <teodor@sigaev.ru>
Date: Wed, 31 Jan 2007 15:09:45 +0000 (+0000)
Subject: Allow GIN's extractQuery method to signal that nothing can satisfy the query.
X-Git-Tag: REL8_3_BETA1~1375
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d4c6da152782b580b24cd8b4054eb1b7fb72c5a0;p=postgresql
Allow GIN's extractQuery method to signal that nothing can satisfy the query.
In this case extractQuery should returns -1 as nentries. This changes
prototype of extractQuery method to use int32* instead of uint32* for
nentries argument.
Based on that gincostestimate may see two corner cases: nothing will be found
or seqscan should be used.
Per proposal at http://archives.postgresql.org/pgsql-hackers/2007-01/msg01581.php
PS tsearch_core patch should be sightly modified to support changes, but I'm
waiting a verdict about reviewing of tsearch_core patch.
---
diff --git a/contrib/intarray/_int_gin.c b/contrib/intarray/_int_gin.c
index 7bb9599b33..2248428786 100644
--- a/contrib/intarray/_int_gin.c
+++ b/contrib/intarray/_int_gin.c
@@ -6,7 +6,7 @@ Datum ginint4_queryextract(PG_FUNCTION_ARGS);
Datum
ginint4_queryextract(PG_FUNCTION_ARGS)
{
- uint32 *nentries = (uint32 *) PG_GETARG_POINTER(1);
+ int32 *nentries = (int32 *) PG_GETARG_POINTER(1);
StrategyNumber strategy = PG_GETARG_UINT16(2);
Datum *res = NULL;
@@ -57,6 +57,19 @@ ginint4_queryextract(PG_FUNCTION_ARGS)
}
}
+ if ( nentries == 0 )
+ {
+ switch( strategy )
+ {
+ case BooleanSearchStrategy:
+ case RTOverlapStrategyNumber:
+ *nentries = -1; /* nobody can be found */
+ break;
+ default: /* require fullscan: GIN can't find void arrays */
+ break;
+ }
+ }
+
PG_RETURN_POINTER(res);
}
diff --git a/contrib/tsearch2/ginidx.c b/contrib/tsearch2/ginidx.c
index c1bb173e1c..01766923c1 100644
--- a/contrib/tsearch2/ginidx.c
+++ b/contrib/tsearch2/ginidx.c
@@ -21,7 +21,7 @@ Datum
gin_extract_tsvector(PG_FUNCTION_ARGS)
{
tsvector *vector = (tsvector *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
- uint32 *nentries = (uint32 *) PG_GETARG_POINTER(1);
+ int32 *nentries = (int32 *) PG_GETARG_POINTER(1);
Datum *entries = NULL;
*nentries = 0;
@@ -30,7 +30,7 @@ gin_extract_tsvector(PG_FUNCTION_ARGS)
int i;
WordEntry *we = ARRPTR(vector);
- *nentries = (uint32) vector->size;
+ *nentries = (int32) vector->size;
entries = (Datum *) palloc(sizeof(Datum) * vector->size);
for (i = 0; i < vector->size; i++)
@@ -58,7 +58,7 @@ Datum
gin_extract_tsquery(PG_FUNCTION_ARGS)
{
QUERYTYPE *query = (QUERYTYPE *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
- uint32 *nentries = (uint32 *) PG_GETARG_POINTER(1);
+ int32 *nentries = (int32 *) PG_GETARG_POINTER(1);
StrategyNumber strategy = DatumGetUInt16(PG_GETARG_DATUM(2));
Datum *entries = NULL;
@@ -99,6 +99,8 @@ gin_extract_tsquery(PG_FUNCTION_ARGS)
}
}
+ else
+ *nentries = -1; /* nothing can be found */
PG_FREE_IF_COPY(query, 0);
PG_RETURN_POINTER(entries);
diff --git a/doc/src/sgml/gin.sgml b/doc/src/sgml/gin.sgml
index c2bbad42bf..32919e5871 100644
--- a/doc/src/sgml/gin.sgml
+++ b/doc/src/sgml/gin.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/gin.sgml,v 2.7 2006/12/01 23:46:46 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/gin.sgml,v 2.8 2007/01/31 15:09:45 teodor Exp $ -->
<chapter id="GIN">
<title>GIN Indexes</title>
@@ -77,7 +77,7 @@
</varlistentry>
<varlistentry>
- <term>Datum* extractValue(Datum inputValue, uint32 *nkeys)</term>
+ <term>Datum* extractValue(Datum inputValue, int32 *nkeys)</term>
<listitem>
<para>
Returns an array of keys given a value to be indexed. The
@@ -87,7 +87,7 @@
</varlistentry>
<varlistentry>
- <term>Datum* extractQuery(Datum query, uint32 *nkeys,
+ <term>Datum* extractQuery(Datum query, int32 *nkeys,
StrategyNumber n)</term>
<listitem>
<para>
@@ -100,6 +100,12 @@
to consult <literal>n</> to determine the data type of
<literal>query</> and the key values that need to be extracted.
The number of returned keys must be stored into <literal>*nkeys</>.
+ If number of keys is equal to zero then <function>extractQuery</>
+ should store 0 or -1 into <literal>*nkeys</>. 0 means that any
+ row matches the <literal>query</> and sequence scan should be
+ produced. -1 means nothing can satisfy <literal>query</>.
+ Choice of value should be based on semantics meaning of operation with
+ given strategy number.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/access/gin/ginarrayproc.c b/src/backend/access/gin/ginarrayproc.c
index fd505333bc..a46def63c5 100644
--- a/src/backend/access/gin/ginarrayproc.c
+++ b/src/backend/access/gin/ginarrayproc.c
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/gin/ginarrayproc.c,v 1.8 2007/01/05 22:19:21 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/gin/ginarrayproc.c,v 1.9 2007/01/31 15:09:45 teodor Exp $
*-------------------------------------------------------------------------
*/
#include "postgres.h"
@@ -38,7 +38,7 @@ Datum
ginarrayextract(PG_FUNCTION_ARGS)
{
ArrayType *array;
- uint32 *nentries = (uint32 *) PG_GETARG_POINTER(1);
+ int32 *nentries = (int32 *) PG_GETARG_POINTER(1);
Datum *entries = NULL;
int16 elmlen;
bool elmbyval;
@@ -60,6 +60,21 @@ ginarrayextract(PG_FUNCTION_ARGS)
elmlen, elmbyval, elmalign,
&entries, NULL, (int *) nentries);
+ if ( *nentries == 0 && PG_NARGS() == 3 )
+ {
+ switch( PG_GETARG_UINT16(2) )
+ {
+ case GinOverlapStrategy:
+ *nentries = -1; /* nobody can be found */
+ break;
+ case GinContainsStrategy:
+ case GinContainedStrategy:
+ case GinEqualStrategy:
+ default: /* require fullscan: GIN can't find void arrays */
+ break;
+ }
+ }
+
/* we should not free array, entries[i] points into it */
PG_RETURN_POINTER(entries);
}
diff --git a/src/backend/access/gin/ginbulk.c b/src/backend/access/gin/ginbulk.c
index f45d5b6395..d3b6f0bceb 100644
--- a/src/backend/access/gin/ginbulk.c
+++ b/src/backend/access/gin/ginbulk.c
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/gin/ginbulk.c,v 1.7 2007/01/05 22:19:21 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/gin/ginbulk.c,v 1.8 2007/01/31 15:09:45 teodor Exp $
*-------------------------------------------------------------------------
*/
@@ -191,13 +191,13 @@ ginChooseElem(BuildAccumulator *accum, ItemPointer heapptr, Datum *entries, uint
* next middle on left part and middle of right part.
*/
void
-ginInsertRecordBA(BuildAccumulator *accum, ItemPointer heapptr, Datum *entries, uint32 nentry)
+ginInsertRecordBA(BuildAccumulator *accum, ItemPointer heapptr, Datum *entries, int32 nentry)
{
uint32 i,
nbit = 0,
offset;
- if (nentry == 0)
+ if (nentry <= 0)
return;
i = nentry - 1;
diff --git a/src/backend/access/gin/ginget.c b/src/backend/access/gin/ginget.c
index 11f034bb21..2366f3f727 100644
--- a/src/backend/access/gin/ginget.c
+++ b/src/backend/access/gin/ginget.c
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/gin/ginget.c,v 1.5 2007/01/05 22:19:21 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/gin/ginget.c,v 1.6 2007/01/31 15:09:45 teodor Exp $
*-------------------------------------------------------------------------
*/
@@ -420,6 +420,7 @@ scanGetItem(IndexScanDesc scan, ItemPointerData *item)
}
#define GinIsNewKey(s) ( ((GinScanOpaque) scan->opaque)->keys == NULL )
+#define GinIsVoidRes(s) ( ((GinScanOpaque) scan->opaque)->isVoidRes == true )
Datum
gingetmulti(PG_FUNCTION_ARGS)
@@ -432,10 +433,13 @@ gingetmulti(PG_FUNCTION_ARGS)
if (GinIsNewKey(scan))
newScanKey(scan);
- startScan(scan);
-
*returned_tids = 0;
+ if (GinIsVoidRes(scan))
+ PG_RETURN_BOOL(false);
+
+ startScan(scan);
+
do
{
if (scanGetItem(scan, tids + *returned_tids))
@@ -462,6 +466,9 @@ gingettuple(PG_FUNCTION_ARGS)
if (GinIsNewKey(scan))
newScanKey(scan);
+ if (GinIsVoidRes(scan))
+ PG_RETURN_BOOL(false);
+
startScan(scan);
res = scanGetItem(scan, &scan->xs_ctup.t_self);
stopScan(scan);
diff --git a/src/backend/access/gin/gininsert.c b/src/backend/access/gin/gininsert.c
index a7ded0c47f..3a17233ba8 100644
--- a/src/backend/access/gin/gininsert.c
+++ b/src/backend/access/gin/gininsert.c
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/gin/gininsert.c,v 1.6 2007/01/05 22:19:21 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/gin/gininsert.c,v 1.7 2007/01/31 15:09:45 teodor Exp $
*-------------------------------------------------------------------------
*/
@@ -203,7 +203,7 @@ static uint32
ginHeapTupleBulkInsert(GinBuildState *buildstate, Datum value, ItemPointer heapptr)
{
Datum *entries;
- uint32 nentries;
+ int32 nentries;
MemoryContext oldCtx;
oldCtx = MemoryContextSwitchTo(buildstate->funcCtx);
@@ -356,7 +356,7 @@ static uint32
ginHeapTupleInsert(Relation index, GinState *ginstate, Datum value, ItemPointer item)
{
Datum *entries;
- uint32 i,
+ int32 i,
nentries;
entries = extractEntriesSU(ginstate, value, &nentries);
diff --git a/src/backend/access/gin/ginscan.c b/src/backend/access/gin/ginscan.c
index bc8c5595f9..22896bc5d7 100644
--- a/src/backend/access/gin/ginscan.c
+++ b/src/backend/access/gin/ginscan.c
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/gin/ginscan.c,v 1.8 2007/01/05 22:19:21 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/gin/ginscan.c,v 1.9 2007/01/31 15:09:45 teodor Exp $
*-------------------------------------------------------------------------
*/
@@ -145,10 +145,12 @@ newScanKey(IndexScanDesc scan)
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("GIN indexes do not support whole-index scans")));
+ so->isVoidRes = false;
+
for (i = 0; i < scan->numberOfKeys; i++)
{
Datum *entryValues;
- uint32 nEntryValues;
+ int32 nEntryValues;
if (scankey[i].sk_flags & SK_ISNULL)
elog(ERROR, "Gin doesn't support NULL as scan key");
@@ -162,6 +164,15 @@ newScanKey(IndexScanDesc scan)
UInt16GetDatum(scankey[i].sk_strategy)
)
);
+ if ( nEntryValues < 0 )
+ {
+ /*
+ * extractQueryFn signals that nothing will be found,
+ * so we can just set isVoidRes flag...
+ */
+ so->isVoidRes = true;
+ break;
+ }
if (entryValues == NULL || nEntryValues == 0)
/* full scan... */
continue;
@@ -173,7 +184,7 @@ newScanKey(IndexScanDesc scan)
so->nkeys = nkeys;
- if (so->nkeys == 0)
+ if (so->nkeys == 0 && !so->isVoidRes)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("GIN index does not support search with void query")));
diff --git a/src/backend/access/gin/ginutil.c b/src/backend/access/gin/ginutil.c
index a14900e56c..e704e8051e 100644
--- a/src/backend/access/gin/ginutil.c
+++ b/src/backend/access/gin/ginutil.c
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/gin/ginutil.c,v 1.9 2007/01/05 22:19:21 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/gin/ginutil.c,v 1.10 2007/01/31 15:09:45 teodor Exp $
*-------------------------------------------------------------------------
*/
@@ -148,7 +148,7 @@ cmpEntries(const Datum *a, const Datum *b, cmpEntriesData *arg)
}
Datum *
-extractEntriesS(GinState *ginstate, Datum value, uint32 *nentries,
+extractEntriesS(GinState *ginstate, Datum value, int32 *nentries,
bool *needUnique)
{
Datum *entries;
@@ -178,7 +178,7 @@ extractEntriesS(GinState *ginstate, Datum value, uint32 *nentries,
Datum *
-extractEntriesSU(GinState *ginstate, Datum value, uint32 *nentries)
+extractEntriesSU(GinState *ginstate, Datum value, int32 *nentries)
{
bool needUnique;
Datum *entries = extractEntriesS(ginstate, value, nentries,
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 0780e52a89..e035557ff2 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.223 2007/01/28 02:53:34 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.224 2007/01/31 15:09:45 teodor Exp $
*
*-------------------------------------------------------------------------
*/
@@ -76,6 +76,7 @@
#include <ctype.h>
#include <math.h>
+#include "access/gin.h"
#include "catalog/pg_opfamily.h"
#include "catalog/pg_statistic.h"
#include "catalog/pg_type.h"
@@ -5286,7 +5287,120 @@ gincostestimate(PG_FUNCTION_ARGS)
Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(5);
Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(6);
double *indexCorrelation = (double *) PG_GETARG_POINTER(7);
+ ListCell *l;
+ int32 nfullscan = 0;
+
+ /*
+ * GIN doesn't support full index scan.
+ * If quals require full index scan then we should
+ * return cost big as possible to forbid full index scan.
+ */
+
+ foreach(l, indexQuals)
+ {
+ RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
+ Expr *clause;
+ Node *leftop,
+ *rightop,
+ *operand;
+ Oid extractProcOid;
+ Oid clause_op;
+ int strategy_op;
+ Oid lefttype,
+ righttype;
+ bool recheck;
+ int32 nentries;
+
+ /*
+ * For each clause it's needed to check operand
+ * for values to search in GIN. So, we should find
+ * extractQuery method to get values from operand
+ */
+
+ Assert(IsA(rinfo, RestrictInfo));
+ clause = rinfo->clause;
+ Assert( IsA(clause, OpExpr) );
+ leftop = get_leftop(clause);
+ rightop = get_rightop(clause);
+ clause_op = ((OpExpr *) clause)->opno;
+
+ if (match_index_to_operand(leftop, 0 /* GiN has only one column */, index))
+ {
+ operand = rightop;
+ }
+ else if (match_index_to_operand(rightop, 0, index))
+ {
+ operand = leftop;
+ clause_op = get_commutator(clause_op);
+ }
+
+ if ( IsA(operand, RelabelType) )
+ operand = (Node *) ((RelabelType *) operand)->arg;
+
+ /*
+ * It's impossible to call extractQuery method for not yet
+ * known operand (taken from table, for example). In this
+ * case we can't do anything useful...
+ */
+ if ( !IsA(operand, Const) )
+ continue;
+
+ if (!op_in_opfamily(clause_op, index->opfamily[0]))
+ continue;
+
+ /*
+ * lefttype is a type of index column, righttype is a
+ * type of operand (query)
+ */
+ get_op_opfamily_properties( clause_op, index->opfamily[0],
+ &strategy_op, &lefttype, &righttype, &recheck);
+
+ /*
+ * GIN (as GiST) always has lefttype == righttype in pg_amproc
+ * and they are equal to type Oid on which index was created/designed
+ */
+ extractProcOid = get_opfamily_proc( index->opfamily[0],
+ lefttype, lefttype,
+ GIN_EXTRACTQUERY_PROC );
+
+ if ( !OidIsValid(extractProcOid) )
+ continue; /* should not be */
+
+ OidFunctionCall3( extractProcOid,
+ ((Const*)operand)->constvalue,
+ PointerGetDatum(&nentries),
+ UInt16GetDatum(strategy_op));
+
+ if ( nentries == 0 )
+ nfullscan++;
+ else if ( nentries < 0 )
+ {
+ /*
+ * GIN_EXTRACTQUERY_PROC guarantees that nothing will be found
+ */
+ *indexStartupCost = 0;
+ *indexTotalCost = 0;
+ *indexSelectivity = 0;
+ *indexCorrelation = 0;
+ PG_RETURN_VOID();
+ }
+ }
+
+ if ( nfullscan == list_length(indexQuals) )
+ {
+ /*
+ * All quals are void and require full scan. So
+ * set max possible cost to prevent index scan.
+ */
+ *indexStartupCost = disable_cost;
+ *indexTotalCost = disable_cost;
+ *indexSelectivity = 1.0;
+ *indexCorrelation = 0;
+
+ PG_RETURN_VOID();
+ }
+
genericcostestimate(root, index, indexQuals, outer_rel, 0.0,
indexStartupCost, indexTotalCost,
indexSelectivity, indexCorrelation);
diff --git a/src/include/access/gin.h b/src/include/access/gin.h
index c37b367278..80f2374996 100644
--- a/src/include/access/gin.h
+++ b/src/include/access/gin.h
@@ -3,7 +3,7 @@
* header file for postgres inverted index access method implementation.
*
* Copyright (c) 2006, PostgreSQL Global Development Group
- * $PostgreSQL: pgsql/src/include/access/gin.h,v 1.9 2006/10/05 17:57:40 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/access/gin.h,v 1.10 2007/01/31 15:09:45 teodor Exp $
*--------------------------------------------------------------------------
*/
@@ -233,8 +233,8 @@ extern void GinInitBuffer(Buffer b, uint32 f);
extern void GinInitPage(Page page, uint32 f, Size pageSize);
extern int compareEntries(GinState *ginstate, Datum a, Datum b);
extern Datum *extractEntriesS(GinState *ginstate, Datum value,
- uint32 *nentries, bool *needUnique);
-extern Datum *extractEntriesSU(GinState *ginstate, Datum value, uint32 *nentries);
+ int32 *nentries, bool *needUnique);
+extern Datum *extractEntriesSU(GinState *ginstate, Datum value, int32 *nentries);
extern Page GinPageGetCopyPage(Page page);
/* gininsert.c */
@@ -399,6 +399,8 @@ typedef struct GinScanOpaqueData
GinScanKey keys;
uint32 nkeys;
+ bool isVoidRes; /* true if ginstate.extractQueryFn
+ guarantees that nothing will be found */
GinScanKey markPos;
} GinScanOpaqueData;
@@ -458,7 +460,7 @@ typedef struct
extern void ginInitBA(BuildAccumulator *accum);
extern void ginInsertRecordBA(BuildAccumulator *accum,
- ItemPointer heapptr, Datum *entries, uint32 nentry);
+ ItemPointer heapptr, Datum *entries, int32 nentry);
extern ItemPointerData *ginGetEntry(BuildAccumulator *accum, Datum *entry, uint32 *n);
#endif