Add operator strategy and comparison-value datatype fields to ScanKey.

Remove the 'strategy map' code, which was a large amount of mechanism
that no longer had any use except reverse-mapping from procedure OID to
strategy number.  Passing the strategy number to the index AM in the
first place is simpler and faster.
This is a preliminary step in planned support for cross-datatype index
operations.  I'm committing it now since the ScanKeyEntryInitialize()
API change touches quite a lot of files, and I want to commit those
changes before the tree drifts under me.

15 files changed, 107 insertions, 231 deletions

diff --git a/src/include/access/gist.h b/src/include/access/gist.h
index fbe3e5a9f20..9aa6991a0d5 100644
--- a/src/include/access/gist.h
+++ b/src/include/access/gist.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: gist.h,v 1.37 2003/08/04 02:40:10 momjian Exp $
+ * $Id: gist.h,v 1.38 2003/11/09 21:30:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -175,8 +175,6 @@ extern void freeGISTstate(GISTSTATE *giststate);
 extern void gistdentryinit(GISTSTATE *giststate, int nkey, GISTENTRY *e,
 			   Datum k, Relation r, Page pg, OffsetNumber o,
 			   int b, bool l, bool isNull);
-extern StrategyNumber RelationGetGISTStrategy(Relation, AttrNumber,
-						RegProcedure);
 
 extern void gist_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void gist_undo(XLogRecPtr lsn, XLogRecord *record);
diff --git a/src/include/access/istrat.h b/src/include/access/istrat.h
deleted file mode 100644
index b538d2aae09..00000000000
--- a/src/include/access/istrat.h
+++ /dev/null
@@ -1,61 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * istrat.h
- *	  POSTGRES index strategy definitions.
- *
- *
- * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * $Id: istrat.h,v 1.27 2003/08/04 02:40:10 momjian Exp $
- *
- *-------------------------------------------------------------------------
- */
-#ifndef ISTRAT_H
-#define ISTRAT_H
-
-#include "utils/rel.h"
-
-/*
- * StrategyNumberIsValid
- *		True iff the strategy number is valid.
- */
-#define StrategyNumberIsValid(strategyNumber) \
-	((bool) ((strategyNumber) != InvalidStrategy))
-
-/*
- * StrategyNumberIsInBounds
- *		True iff strategy number is within given bounds.
- *
- * Note:
- *		Assumes StrategyNumber is an unsigned type.
- *		Assumes the bounded interval to be (0,max].
- */
-#define StrategyNumberIsInBounds(strategyNumber, maxStrategyNumber) \
-	((bool)(InvalidStrategy < (strategyNumber) && \
-			(strategyNumber) <= (maxStrategyNumber)))
-
-/*
- * StrategyMapIsValid
- *		True iff the index strategy mapping is valid.
- */
-#define StrategyMapIsValid(map) PointerIsValid(map)
-
-/*
- * IndexStrategyIsValid
- *		True iff the index strategy is valid.
- */
-#define IndexStrategyIsValid(s) PointerIsValid(s)
-
-extern ScanKey StrategyMapGetScanKeyEntry(StrategyMap map,
-						   StrategyNumber strategyNumber);
-extern StrategyMap IndexStrategyGetStrategyMap(IndexStrategy indexStrategy,
-					  StrategyNumber maxStrategyNum, AttrNumber attrNum);
-
-extern Size AttributeNumberGetIndexStrategySize(AttrNumber maxAttributeNumber,
-									StrategyNumber maxStrategyNumber);
-extern StrategyNumber RelationGetStrategy(Relation relation,
-			   AttrNumber attributeNumber, StrategyEvaluation evaluation,
-					RegProcedure procedure);
-
-#endif   /* ISTRAT_H */
diff --git a/src/include/access/nbtree.h b/src/include/access/nbtree.h
index a852fa24925..80d412a52e5 100644
--- a/src/include/access/nbtree.h
+++ b/src/include/access/nbtree.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nbtree.h,v 1.71 2003/09/29 23:40:26 tgl Exp $
+ * $Id: nbtree.h,v 1.72 2003/11/09 21:30:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -340,16 +340,10 @@ typedef struct xl_btree_newpage
 
 
 /*
- *	Operator strategy numbers -- ordering of these is <, <=, =, >=, >
+ *	Operator strategy numbers for B-tree have been moved to access/skey.h,
+ *	because many places need to use them in ScanKeyEntryInitialize() calls.
  */
 
-#define BTLessStrategyNumber			1
-#define BTLessEqualStrategyNumber		2
-#define BTEqualStrategyNumber			3
-#define BTGreaterEqualStrategyNumber	4
-#define BTGreaterStrategyNumber			5
-#define BTMaxStrategyNumber				5
-
 /*
  *	When a new operator class is declared, we require that the user
  *	supply us with an amproc procedure for determining whether, for
@@ -480,12 +474,6 @@ extern bool _bt_step(IndexScanDesc scan, Buffer *bufP, ScanDirection dir);
 extern Buffer _bt_get_endpoint(Relation rel, uint32 level, bool rightmost);
 
 /*
- * prototypes for functions in nbtstrat.c
- */
-extern StrategyNumber _bt_getstrat(Relation rel, AttrNumber attno,
-			 RegProcedure proc);
-
-/*
  * prototypes for functions in nbtutils.c
  */
 extern ScanKey _bt_mkscankey(Relation rel, IndexTuple itup);
diff --git a/src/include/access/relscan.h b/src/include/access/relscan.h
index 63c6bcc56bc..d56b2ac958b 100644
--- a/src/include/access/relscan.h
+++ b/src/include/access/relscan.h
@@ -7,13 +7,14 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: relscan.h,v 1.32 2003/08/04 02:40:10 momjian Exp $
+ * $Id: relscan.h,v 1.33 2003/11/09 21:30:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef RELSCAN_H
 #define RELSCAN_H
 
+#include "access/skey.h"
 #include "utils/tqual.h"
 
 
diff --git a/src/include/access/rtree.h b/src/include/access/rtree.h
index ed8dd6cf2e1..846090204aa 100644
--- a/src/include/access/rtree.h
+++ b/src/include/access/rtree.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: rtree.h,v 1.30 2003/08/04 02:40:10 momjian Exp $
+ * $Id: rtree.h,v 1.31 2003/11/09 21:30:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -132,7 +132,6 @@ extern void rtadjscans(Relation r, int op, BlockNumber blkno,
 extern void AtEOXact_rtree(void);
 
 /* rtstrat.c */
-extern RegProcedure RTMapOperator(Relation r, AttrNumber attnum,
-			  RegProcedure proc);
+extern StrategyNumber RTMapToInternalOperator(StrategyNumber strat);
 
 #endif   /* RTREE_H */
diff --git a/src/include/access/skey.h b/src/include/access/skey.h
index 2e66cfd894a..b7373dd6410 100644
--- a/src/include/access/skey.h
+++ b/src/include/access/skey.h
@@ -7,10 +7,8 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: skey.h,v 1.22 2003/08/04 02:40:10 momjian Exp $
+ * $Id: skey.h,v 1.23 2003/11/09 21:30:37 tgl Exp $
  *
- * Note:
- *		Needs more accessor/assignment routines.
  *-------------------------------------------------------------------------
  */
 #ifndef SKEY_H
@@ -20,32 +18,77 @@
 #include "fmgr.h"
 
 
+/*
+ * Strategy numbers identify the semantics that particular operators have
+ * with respect to particular operator classes.
+ */
+typedef uint16 StrategyNumber;
+
+#define InvalidStrategy ((StrategyNumber) 0)
+
+/*
+ * We define the strategy numbers for B-tree indexes here, to avoid having
+ * to import access/nbtree.h into a lot of places that shouldn't need it.
+ */
+#define BTLessStrategyNumber			1
+#define BTLessEqualStrategyNumber		2
+#define BTEqualStrategyNumber			3
+#define BTGreaterEqualStrategyNumber	4
+#define BTGreaterStrategyNumber			5
+
+#define BTMaxStrategyNumber				5
+
+
+/*
+ * A ScanKey represents the application of a comparison operator between
+ * a table or index column and a constant.  When it's part of an array of
+ * ScanKeys, the comparison conditions are implicitly ANDed.  The index
+ * column is the left argument of the operator, if it's a binary operator.
+ * (The data structure can support unary indexable operators too; in that
+ * case sk_argument would go unused.  This is not currently implemented.)
+ *
+ * For an index scan, sk_strategy must be set correctly for the operator.
+ * When using a ScanKey in a heap scan, sk_strategy is not used and may be
+ * set to InvalidStrategy.
+ *
+ * Note: in some places, ScanKeys are used as a convenient representation
+ * for the invocation of an access method support procedure.  In this case
+ * sk_strategy is not meaningful, and sk_func may refer to a function that
+ * returns something other than boolean.
+ */
 typedef struct ScanKeyData
 {
-	bits16		sk_flags;		/* flags */
-	AttrNumber	sk_attno;		/* domain number */
-	RegProcedure sk_procedure;	/* procedure OID */
-	FmgrInfo	sk_func;		/* fmgr call info for procedure */
+	int			sk_flags;		/* flags, see below */
+	AttrNumber	sk_attno;		/* table or index column number */
+	StrategyNumber sk_strategy;	/* operator strategy number */
+	FmgrInfo	sk_func;		/* lookup info for function to call */
 	Datum		sk_argument;	/* data to compare */
+	Oid			sk_argtype;		/* datatype of sk_argument */
 } ScanKeyData;
 
 typedef ScanKeyData *ScanKey;
 
-/* ScanKeyData flags */
-#define SK_ISNULL		0x1		/* sk_argument is NULL */
-#define SK_UNARY		0x2		/* unary function (currently unsupported) */
-#define SK_NEGATE		0x4		/* negate function result */
-#define SK_COMMUTE		0x8		/* commute function (not fully supported) */
+/* ScanKeyData sk_flags */
+#define SK_ISNULL		0x0001	/* sk_argument is NULL */
+#define SK_UNARY		0x0002	/* unary operator (currently unsupported) */
 
 
 /*
  * prototypes for functions in access/common/scankey.c
  */
-extern void ScanKeyEntrySetIllegal(ScanKey entry);
-extern void ScanKeyEntryInitialize(ScanKey entry, bits16 flags,
-	 AttrNumber attributeNumber, RegProcedure procedure, Datum argument);
-extern void ScanKeyEntryInitializeWithInfo(ScanKey entry, bits16 flags,
-							 AttrNumber attributeNumber, FmgrInfo *finfo,
-							   MemoryContext mcxt, Datum argument);
+extern void ScanKeyEntryInitialize(ScanKey entry,
+								   int flags,
+								   AttrNumber attributeNumber,
+								   StrategyNumber strategy,
+								   RegProcedure procedure,
+								   Datum argument,
+								   Oid argtype);
+extern void ScanKeyEntryInitializeWithInfo(ScanKey entry,
+										   int flags,
+										   AttrNumber attributeNumber,
+										   StrategyNumber strategy,
+										   FmgrInfo *finfo,
+										   Datum argument,
+										   Oid argtype);
 
 #endif   /* SKEY_H */
diff --git a/src/include/access/strat.h b/src/include/access/strat.h
deleted file mode 100644
index f697f79e4ee..00000000000
--- a/src/include/access/strat.h
+++ /dev/null
@@ -1,90 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * strat.h
- *	  index strategy type definitions
- *	  (separated out from original istrat.h to avoid circular refs)
- *
- *
- * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * $Id: strat.h,v 1.27 2003/08/04 02:40:10 momjian Exp $
- *
- *-------------------------------------------------------------------------
- */
-#ifndef STRAT_H
-#define STRAT_H
-
-#include "access/skey.h"
-
-
-typedef uint16 StrategyNumber;
-
-#define InvalidStrategy 0
-
-typedef struct StrategyTransformMapData
-{
-	StrategyNumber strategy[1]; /* VARIABLE LENGTH ARRAY */
-} StrategyTransformMapData;		/* VARIABLE LENGTH STRUCTURE */
-
-typedef StrategyTransformMapData *StrategyTransformMap;
-
-typedef struct StrategyOperatorData
-{
-	StrategyNumber strategy;
-	bits16		flags;			/* scan qualification flags, see skey.h */
-} StrategyOperatorData;
-
-typedef StrategyOperatorData *StrategyOperator;
-
-typedef struct StrategyTermData
-{								/* conjunctive term */
-	uint16		degree;
-	StrategyOperatorData operatorData[1];		/* VARIABLE LENGTH ARRAY */
-} StrategyTermData;				/* VARIABLE LENGTH STRUCTURE */
-
-typedef StrategyTermData *StrategyTerm;
-
-typedef struct StrategyExpressionData
-{								/* disjunctive normal form */
-	StrategyTerm term[1];		/* VARIABLE LENGTH ARRAY */
-} StrategyExpressionData;		/* VARIABLE LENGTH STRUCTURE */
-
-typedef StrategyExpressionData *StrategyExpression;
-
-typedef struct StrategyEvaluationData
-{
-	StrategyNumber maxStrategy;
-	/* each of these must point to an array of maxStrategy elements: */
-	StrategyTransformMap negateTransform;
-	StrategyTransformMap commuteTransform;
-	StrategyTransformMap negateCommuteTransform;
-	StrategyExpression *expression;
-} StrategyEvaluationData;
-
-typedef StrategyEvaluationData *StrategyEvaluation;
-
-/*
- * StrategyTransformMapIsValid
- *		Returns true iff strategy transformation map is valid.
- */
-#define StrategyTransformMapIsValid(transform) PointerIsValid(transform)
-
-
-#define AMStrategies(foo)		(foo)
-
-typedef struct StrategyMapData
-{
-	ScanKeyData entry[1];		/* VARIABLE LENGTH ARRAY */
-} StrategyMapData;				/* VARIABLE LENGTH STRUCTURE */
-
-typedef StrategyMapData *StrategyMap;
-
-typedef struct IndexStrategyData
-{
-	StrategyMapData strategyMapData[1]; /* VARIABLE LENGTH ARRAY */
-} IndexStrategyData;			/* VARIABLE LENGTH STRUCTURE */
-
-typedef IndexStrategyData *IndexStrategy;
-
-#endif   /* STRAT_H */
diff --git a/src/include/access/valid.h b/src/include/access/valid.h
index 3109d3e7e4d..e16a392a243 100644
--- a/src/include/access/valid.h
+++ b/src/include/access/valid.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: valid.h,v 1.31 2003/09/25 18:58:35 tgl Exp $
+ * $Id: valid.h,v 1.32 2003/11/09 21:30:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -31,15 +31,16 @@ do \
 /* We use underscores to protect the variable passed in as parameters */ \
 /* We use two underscore here because this macro is included in the \
    macro below */ \
-	bool		__isnull; \
-	Datum		__atp; \
-	Datum		__test; \
 	int			__cur_nkeys = (nkeys); \
 	ScanKey		__cur_keys = (keys); \
  \
 	(result) = true; /* may change */ \
 	for (; __cur_nkeys--; __cur_keys++) \
 	{ \
+		Datum	__atp; \
+		bool	__isnull; \
+		Datum	__test; \
+ \
 		__atp = heap_getattr((tuple), \
 							 __cur_keys->sk_attno, \
 							 (tupdesc), \
@@ -58,16 +59,11 @@ do \
 			break; \
 		} \
  \
-		if (__cur_keys->sk_flags & SK_COMMUTE) \
-			__test = FunctionCall2(&__cur_keys->sk_func, \
-								   __cur_keys->sk_argument, __atp); \
-		else \
-			__test = FunctionCall2(&__cur_keys->sk_func, \
-								   __atp, __cur_keys->sk_argument); \
+		__test = FunctionCall2(&__cur_keys->sk_func, \
+							   __atp, __cur_keys->sk_argument); \
  \
-		if (DatumGetBool(__test) == !!(__cur_keys->sk_flags & SK_NEGATE)) \
+		if (!DatumGetBool(__test)) \
 		{ \
-			/* XXX eventually should check if SK_ISNULL */ \
 			(result) = false; \
 			break; \
 		} \
diff --git a/src/include/commands/sequence.h b/src/include/commands/sequence.h
index 531e30bb6ce..8c83fec3cc7 100644
--- a/src/include/commands/sequence.h
+++ b/src/include/commands/sequence.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: sequence.h,v 1.26 2003/08/08 21:42:41 momjian Exp $
+ * $Id: sequence.h,v 1.27 2003/11/09 21:30:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,6 +15,8 @@
 
 #include "nodes/parsenodes.h"
 #include "access/xlog.h"
+#include "fmgr.h"
+
 
 /*
  * On a machine with no 64-bit-int C datatype, sizeof(int64) will not be 8,
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index f56dc4653de..2312c0562e3 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: plannodes.h,v 1.68 2003/08/08 21:42:48 momjian Exp $
+ * $Id: plannodes.h,v 1.69 2003/11/09 21:30:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -153,15 +153,19 @@ typedef Scan SeqScan;
 
 /* ----------------
  *		index scan node
+ *
+ * Note: this can actually represent N indexscans, all on the same table
+ * but potentially using different indexes, put together with OR semantics.
  * ----------------
  */
 typedef struct IndexScan
 {
 	Scan		scan;
-	List	   *indxid;
-	List	   *indxqual;
-	List	   *indxqualorig;
-	ScanDirection indxorderdir;
+	List	   *indxid;			/* list of index OIDs (1 per scan) */
+	List	   *indxqual;		/* list of sublists of index quals */
+	List	   *indxqualorig;	/* the same in original form */
+	List	   *indxstrategy;	/* list of sublists of strategy numbers */
+	ScanDirection indxorderdir;	/* forward or backward or don't care */
 } IndexScan;
 
 /* ----------------
diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h
index 98d357760dc..eed5c5ee9f3 100644
--- a/src/include/pg_config_manual.h
+++ b/src/include/pg_config_manual.h
@@ -6,7 +6,7 @@
  * for developers.	If you edit any of these, be sure to do a *full*
  * rebuild (and an initdb if noted).
  *
- * $Id: pg_config_manual.h,v 1.6 2003/09/21 17:57:21 tgl Exp $
+ * $Id: pg_config_manual.h,v 1.7 2003/11/09 21:30:37 tgl Exp $
  *------------------------------------------------------------------------
  */
 
@@ -229,7 +229,6 @@
  */
 /* #define IPORTAL_DEBUG  */
 /* #define HEAPDEBUGALL  */
-/* #define ISTRATDEBUG	*/
 /* #define ACLDEBUG */
 /* #define RTDEBUG */
 /* #define GISTDEBUG */
diff --git a/src/include/storage/smgr.h b/src/include/storage/smgr.h
index 67b1d4b6ccf..a4d3097dffc 100644
--- a/src/include/storage/smgr.h
+++ b/src/include/storage/smgr.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: smgr.h,v 1.37 2003/08/04 02:40:15 momjian Exp $
+ * $Id: smgr.h,v 1.38 2003/11/09 21:30:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,6 +15,7 @@
 #define SMGR_H
 
 #include "access/xlog.h"
+#include "fmgr.h"
 #include "storage/relfilenode.h"
 #include "storage/block.h"
 #include "utils/rel.h"
diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h
index d61b58a2cd4..df42020c04d 100644
--- a/src/include/utils/catcache.h
+++ b/src/include/utils/catcache.h
@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: catcache.h,v 1.46 2003/08/04 02:40:15 momjian Exp $
+ * $Id: catcache.h,v 1.47 2003/11/09 21:30:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,6 +21,7 @@
 #define CATCACHE_H
 
 #include "access/htup.h"
+#include "access/skey.h"
 #include "lib/dllist.h"
 
 /*
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index d6aaf2c1c25..36146f23d11 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lsyscache.h,v 1.82 2003/10/04 18:22:59 tgl Exp $
+ * $Id: lsyscache.h,v 1.83 2003/11/09 21:30:38 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -25,7 +25,8 @@ typedef enum IOFuncSelector
 } IOFuncSelector;
 
 extern bool op_in_opclass(Oid opno, Oid opclass);
-extern bool op_requires_recheck(Oid opno, Oid opclass);
+extern void get_op_opclass_properties(Oid opno, Oid opclass,
+									  int *strategy, bool *recheck);
 extern Oid	get_opclass_member(Oid opclass, int16 strategy);
 extern Oid	get_op_hash_function(Oid opno);
 extern Oid	get_opclass_proc(Oid opclass, int16 procnum);
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index 377822afc69..f08d6c0f1f8 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -7,14 +7,13 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: rel.h,v 1.68 2003/09/24 18:54:01 tgl Exp $
+ * $Id: rel.h,v 1.69 2003/11/09 21:30:38 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef REL_H
 #define REL_H
 
-#include "access/strat.h"
 #include "access/tupdesc.h"
 #include "catalog/pg_am.h"
 #include "catalog/pg_class.h"
@@ -88,9 +87,8 @@ typedef struct TriggerDesc
 } TriggerDesc;
 
 
-/* ----------
+/*
  * Same for the statistics collector data in Relation and scan data.
- * ----------
  */
 typedef struct PgStat_Info
 {
@@ -138,9 +136,15 @@ typedef struct RelationData
 	/* "struct HeapTupleData *" avoids need to include htup.h here	*/
 	Form_pg_am	rd_am;			/* pg_am tuple for index's AM */
 
-	/* index access support info (used only for an index relation) */
+	/*
+	 * index access support info (used only for an index relation)
+	 *
+	 * Note: only operators and support procs for the index's own datatype
+	 * are cached, not any cross-type operators.  The arrays are indexed by
+	 * strategy or support number, which is a sufficient identifier given
+	 * that restriction.
+	 */
 	MemoryContext rd_indexcxt;	/* private memory cxt for this stuff */
-	IndexStrategy rd_istrat;	/* operator strategy map */
 	Oid		   *rd_operator;	/* OIDs of index operators */
 	RegProcedure *rd_support;	/* OIDs of support procedures */
 	struct FmgrInfo *rd_supportinfo;	/* lookup info for support
@@ -242,16 +246,6 @@ typedef Relation *RelationPtr;
 #define RelationGetDescr(relation) ((relation)->rd_att)
 
 /*
- * RelationGetIndexStrategy
- *		Returns index strategy for a relation.
- *
- * Note:
- *		Assumes relation descriptor is valid.
- *		Assumes relation descriptor is for an index relation.
- */
-#define RelationGetIndexStrategy(relation) ((relation)->rd_istrat)
-
-/*
  * RelationGetRelationName
  *
  *	  Returns the rel's name.