Create a new file executor/execGrouping.c to centralize utility routines

shared by nodeGroup, nodeAgg, and soon nodeSubplan.

src/backend/executor/Makefile

@@ -4,7 +4,7 @@
 #    Makefile for executor
 #
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/backend/executor/Makefile,v 1.19 2002/05/12 23:43:02 tgl Exp $
+#    $Header: /cvsroot/pgsql/src/backend/executor/Makefile,v 1.20 2003/01/10 23:54:24 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -12,7 +12,7 @@ subdir = src/backend/executor
 top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
-OBJS = execAmi.o execJunk.o execMain.o \
+OBJS = execAmi.o execGrouping.o execJunk.o execMain.o \
        execProcnode.o execQual.o execScan.o execTuples.o \
        execUtils.o functions.o instrument.o nodeAppend.o nodeAgg.o nodeHash.o \
        nodeHashjoin.o nodeIndexscan.o nodeMaterial.o nodeMergejoin.o \

src/backend/executor/execGrouping.c

@@ -0,0 +1,369 @@
+/*-------------------------------------------------------------------------
+ *
+ * execGrouping.c
+ *	  executor utility routines for grouping, hashing, and aggregation
+ *
+ * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execGrouping.c,v 1.1 2003/01/10 23:54:24 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/hash.h"
+#include "access/heapam.h"
+#include "executor/executor.h"
+#include "parser/parse_oper.h"
+#include "utils/memutils.h"
+
+
+/*****************************************************************************
+ *		Utility routines for grouping tuples together
+ *
+ * These routines actually implement SQL's notion of "distinct/not distinct".
+ * Two tuples match if they are not distinct in all the compared columns,
+ * i.e., the column values are either both null, or both non-null and equal.
+ *****************************************************************************/
+
+/*
+ * execTuplesMatch
+ *		Return true if two tuples match in all the indicated fields.
+ *		This is used to detect group boundaries in nodeGroup and nodeAgg,
+ *		and to decide whether two tuples are distinct or not in nodeUnique.
+ *
+ * tuple1, tuple2: the tuples to compare
+ * tupdesc: tuple descriptor applying to both tuples
+ * numCols: the number of attributes to be examined
+ * matchColIdx: array of attribute column numbers
+ * eqFunctions: array of fmgr lookup info for the equality functions to use
+ * evalContext: short-term memory context for executing the functions
+ *
+ * NB: evalContext is reset each time!
+ */
+bool
+execTuplesMatch(HeapTuple tuple1,
+				HeapTuple tuple2,
+				TupleDesc tupdesc,
+				int numCols,
+				AttrNumber *matchColIdx,
+				FmgrInfo *eqfunctions,
+				MemoryContext evalContext)
+{
+	MemoryContext oldContext;
+	bool		result;
+	int			i;
+
+	/* Reset and switch into the temp context. */
+	MemoryContextReset(evalContext);
+	oldContext = MemoryContextSwitchTo(evalContext);
+
+	/*
+	 * We cannot report a match without checking all the fields, but we
+	 * can report a non-match as soon as we find unequal fields.  So,
+	 * start comparing at the last field (least significant sort key).
+	 * That's the most likely to be different if we are dealing with
+	 * sorted input.
+	 */
+	result = true;
+
+	for (i = numCols; --i >= 0;)
+	{
+		AttrNumber	att = matchColIdx[i];
+		Datum		attr1,
+					attr2;
+		bool		isNull1,
+					isNull2;
+
+		attr1 = heap_getattr(tuple1,
+							 att,
+							 tupdesc,
+							 &isNull1);
+
+		attr2 = heap_getattr(tuple2,
+							 att,
+							 tupdesc,
+							 &isNull2);
+
+		if (isNull1 != isNull2)
+		{
+			result = false;		/* one null and one not; they aren't equal */
+			break;
+		}
+
+		if (isNull1)
+			continue;			/* both are null, treat as equal */
+
+		/* Apply the type-specific equality function */
+
+		if (!DatumGetBool(FunctionCall2(&eqfunctions[i],
+										attr1, attr2)))
+		{
+			result = false;		/* they aren't equal */
+			break;
+		}
+	}
+
+	MemoryContextSwitchTo(oldContext);
+
+	return result;
+}
+
+
+/*
+ * execTuplesMatchPrepare
+ *		Look up the equality functions needed for execTuplesMatch.
+ *		The result is a palloc'd array.
+ */
+FmgrInfo *
+execTuplesMatchPrepare(TupleDesc tupdesc,
+					   int numCols,
+					   AttrNumber *matchColIdx)
+{
+	FmgrInfo   *eqfunctions = (FmgrInfo *) palloc(numCols * sizeof(FmgrInfo));
+	int			i;
+
+	for (i = 0; i < numCols; i++)
+	{
+		AttrNumber	att = matchColIdx[i];
+		Oid			typid = tupdesc->attrs[att - 1]->atttypid;
+		Oid			eq_function;
+
+		eq_function = equality_oper_funcid(typid);
+		fmgr_info(eq_function, &eqfunctions[i]);
+	}
+
+	return eqfunctions;
+}
+
+
+/*****************************************************************************
+ *		Utility routines for hashing
+ *****************************************************************************/
+
+/*
+ * ComputeHashFunc
+ *
+ *		the hash function for hash joins (also used for hash aggregation)
+ *
+ *		XXX this probably ought to be replaced with datatype-specific
+ *		hash functions, such as those already implemented for hash indexes.
+ */
+uint32
+ComputeHashFunc(Datum key, int typLen, bool byVal)
+{
+	unsigned char *k;
+
+	if (byVal)
+	{
+		/*
+		 * If it's a by-value data type, just hash the whole Datum value.
+		 * This assumes that datatypes narrower than Datum are
+		 * consistently padded (either zero-extended or sign-extended, but
+		 * not random bits) to fill Datum; see the XXXGetDatum macros in
+		 * postgres.h. NOTE: it would not work to do hash_any(&key, len)
+		 * since this would get the wrong bytes on a big-endian machine.
+		 */
+		k = (unsigned char *) &key;
+		typLen = sizeof(Datum);
+	}
+	else
+	{
+		if (typLen > 0)
+		{
+			/* fixed-width pass-by-reference type */
+			k = (unsigned char *) DatumGetPointer(key);
+		}
+		else if (typLen == -1)
+		{
+			/*
+			 * It's a varlena type, so 'key' points to a "struct varlena".
+			 * NOTE: VARSIZE returns the "real" data length plus the
+			 * sizeof the "vl_len" attribute of varlena (the length
+			 * information). 'key' points to the beginning of the varlena
+			 * struct, so we have to use "VARDATA" to find the beginning
+			 * of the "real" data.	Also, we have to be careful to detoast
+			 * the datum if it's toasted.  (We don't worry about freeing
+			 * the detoasted copy; that happens for free when the
+			 * per-tuple memory context is reset in ExecHashGetBucket.)
+			 */
+			struct varlena *vkey = PG_DETOAST_DATUM(key);
+
+			typLen = VARSIZE(vkey) - VARHDRSZ;
+			k = (unsigned char *) VARDATA(vkey);
+		}
+		else if (typLen == -2)
+		{
+			/* It's a null-terminated C string */
+			typLen = strlen(DatumGetCString(key)) + 1;
+			k = (unsigned char *) DatumGetPointer(key);
+		}
+		else
+		{
+			elog(ERROR, "ComputeHashFunc: Invalid typLen %d", typLen);
+			k = NULL;			/* keep compiler quiet */
+		}
+	}
+
+	return DatumGetUInt32(hash_any(k, typLen));
+}
+
+
+/*****************************************************************************
+ *		Utility routines for all-in-memory hash tables
+ *
+ * These routines build hash tables for grouping tuples together (eg, for
+ * hash aggregation).  There is one entry for each not-distinct set of tuples
+ * presented.
+ *****************************************************************************/
+
+/*
+ * Construct an empty TupleHashTable
+ *
+ *	numCols, keyColIdx: identify the tuple fields to use as lookup key
+ *	eqfunctions: equality comparison functions to use
+ *	nbuckets: number of buckets to make
+ *	entrysize: size of each entry (at least sizeof(TupleHashEntryData))
+ *	tablecxt: memory context in which to store table and table entries
+ *	tempcxt: short-lived context for evaluation hash and comparison functions
+ *
+ * The eqfunctions array may be made with execTuplesMatchPrepare().
+ *
+ * Note that keyColIdx and eqfunctions must be allocated in storage that
+ * will live as long as the hashtable does.
+ */
+TupleHashTable
+BuildTupleHashTable(int numCols, AttrNumber *keyColIdx,
+					FmgrInfo *eqfunctions,
+					int nbuckets, Size entrysize,
+					MemoryContext tablecxt, MemoryContext tempcxt)
+{
+	TupleHashTable	hashtable;
+	Size			tabsize;
+
+	Assert(nbuckets > 0);
+	Assert(entrysize >= sizeof(TupleHashEntryData));
+
+	tabsize = sizeof(TupleHashTableData) +
+		(nbuckets - 1) * sizeof(TupleHashEntry);
+	hashtable = (TupleHashTable) MemoryContextAllocZero(tablecxt, tabsize);
+
+	hashtable->numCols = numCols;
+	hashtable->keyColIdx = keyColIdx;
+	hashtable->eqfunctions = eqfunctions;
+	hashtable->tablecxt = tablecxt;
+	hashtable->tempcxt = tempcxt;
+	hashtable->entrysize = entrysize;
+	hashtable->nbuckets = nbuckets;
+
+	return hashtable;
+}
+
+/*
+ * Find or create a hashtable entry for the tuple group containing the
+ * given tuple.
+ *
+ * On return, *isnew is true if the entry is newly created, false if it
+ * existed already.  Any extra space in a new entry has been zeroed.
+ */
+TupleHashEntry
+LookupTupleHashEntry(TupleHashTable hashtable, TupleTableSlot *slot,
+					 bool *isnew)
+{
+	int			numCols = hashtable->numCols;
+	AttrNumber *keyColIdx = hashtable->keyColIdx;
+	HeapTuple	tuple = slot->val;
+	TupleDesc	tupdesc = slot->ttc_tupleDescriptor;
+	uint32		hashkey = 0;
+	int			i;
+	int			bucketno;
+	TupleHashEntry entry;
+	MemoryContext oldContext;
+
+	/* Need to run the hash function in short-lived context */
+	oldContext = MemoryContextSwitchTo(hashtable->tempcxt);
+
+	for (i = 0; i < numCols; i++)
+	{
+		AttrNumber	att = keyColIdx[i];
+		Datum		attr;
+		bool		isNull;
+
+		/* rotate hashkey left 1 bit at each step */
+		hashkey = (hashkey << 1) | ((hashkey & 0x80000000) ? 1 : 0);
+
+		attr = heap_getattr(tuple, att, tupdesc, &isNull);
+		if (isNull)
+			continue;			/* treat nulls as having hash key 0 */
+		hashkey ^= ComputeHashFunc(attr,
+								   (int) tupdesc->attrs[att - 1]->attlen,
+								   tupdesc->attrs[att - 1]->attbyval);
+	}
+	bucketno = hashkey % (uint32) hashtable->nbuckets;
+
+	for (entry = hashtable->buckets[bucketno];
+		 entry != NULL;
+		 entry = entry->next)
+	{
+		/* Quick check using hashkey */
+		if (entry->hashkey != hashkey)
+			continue;
+		if (execTuplesMatch(entry->firstTuple,
+							tuple,
+							tupdesc,
+							numCols, keyColIdx,
+							hashtable->eqfunctions,
+							hashtable->tempcxt))
+		{
+			MemoryContextSwitchTo(oldContext);
+			*isnew = false;
+			return entry;
+		}
+	}
+
+	/* Not there, so build a new one */
+	MemoryContextSwitchTo(hashtable->tablecxt);
+
+	entry = (TupleHashEntry) palloc0(hashtable->entrysize);
+
+	entry->hashkey = hashkey;
+	entry->firstTuple = heap_copytuple(tuple);
+
+	entry->next = hashtable->buckets[bucketno];
+	hashtable->buckets[bucketno] = entry;
+
+	MemoryContextSwitchTo(oldContext);
+
+	*isnew = true;
+
+	return entry;
+}
+
+/*
+ * Walk through all the entries of a hash table, in no special order.
+ * Returns NULL when no more entries remain.
+ *
+ * Iterator state must be initialized with ResetTupleHashIterator() macro.
+ */
+TupleHashEntry
+ScanTupleHashTable(TupleHashTable hashtable, TupleHashIterator *state)
+{
+	TupleHashEntry	entry;
+
+	entry = state->next_entry;
+	while (entry == NULL)
+	{
+		if (state->next_bucket >= hashtable->nbuckets)
+		{
+			/* No more entries in hashtable, so done */
+			return NULL;
+		}
+		entry = hashtable->buckets[state->next_bucket++];
+	}
+	state->next_entry = entry->next;
+
+	return entry;
+}

src/backend/executor/nodeAgg.c

@@ -45,7 +45,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.101 2002/12/15 16:17:46 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.102 2003/01/10 23:54:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -57,8 +57,6 @@
 #include "catalog/pg_operator.h"
 #include "executor/executor.h"
 #include "executor/nodeAgg.h"
-#include "executor/nodeGroup.h"
-#include "executor/nodeHash.h"
 #include "miscadmin.h"
 #include "optimizer/clauses.h"
 #include "parser/parse_coerce.h"
@@ -182,21 +180,15 @@ typedef struct AggStatePerGroupData
  * distinct set of GROUP BY column values.  We compute the hash key from
  * the GROUP BY columns.
  */
+typedef struct AggHashEntryData *AggHashEntry;
+
 typedef struct AggHashEntryData
 {
-	AggHashEntry	next;		/* next entry in same hash bucket */
+	TupleHashEntryData shared;	/* common header for hash table entries */
-	uint32		hashkey;		/* exact hash key of this entry */
-	HeapTuple	firstTuple;		/* copy of first tuple in this group */
 	/* per-aggregate transition status array - must be last! */
 	AggStatePerGroupData pergroup[1];	/* VARIABLE LENGTH ARRAY */
 } AggHashEntryData;				/* VARIABLE LENGTH STRUCT */
 
-typedef struct AggHashTableData
-{
-	int			nbuckets;		/* number of buckets in hash table */
-	AggHashEntry buckets[1];	/* VARIABLE LENGTH ARRAY */
-} AggHashTableData;				/* VARIABLE LENGTH STRUCT */
-
 
 static void initialize_aggregates(AggState *aggstate,
 								  AggStatePerAgg peragg,
@@ -578,18 +570,22 @@ static void
 build_hash_table(AggState *aggstate)
 {
 	Agg			   *node = (Agg *) aggstate->ss.ps.plan;
-	AggHashTable	hashtable;
+	MemoryContext	tmpmem = aggstate->tmpcontext->ecxt_per_tuple_memory;
-	Size			tabsize;
+	Size			entrysize;
 
 	Assert(node->aggstrategy == AGG_HASHED);
 	Assert(node->numGroups > 0);
-	tabsize = sizeof(AggHashTableData) +
+
-		(node->numGroups - 1) * sizeof(AggHashEntry);
+	entrysize = sizeof(AggHashEntryData) +
-	hashtable = (AggHashTable) MemoryContextAlloc(aggstate->aggcontext,
+		(aggstate->numaggs - 1) * sizeof(AggStatePerGroupData);
-												  tabsize);
+
-	MemSet(hashtable, 0, tabsize);
+	aggstate->hashtable = BuildTupleHashTable(node->numCols,
-	hashtable->nbuckets = node->numGroups;
+											  node->grpColIdx,
-	aggstate->hashtable = hashtable;
+											  aggstate->eqfunctions,
+											  node->numGroups,
+											  entrysize,
+											  aggstate->aggcontext,
+											  tmpmem);
 }
 
 /*
@@ -601,75 +597,19 @@ build_hash_table(AggState *aggstate)
 static AggHashEntry
 lookup_hash_entry(AggState *aggstate, TupleTableSlot *slot)
 {
-	Agg		   *node = (Agg *) aggstate->ss.ps.plan;
+	AggHashEntry entry;
-	AggHashTable hashtable = aggstate->hashtable;
+	bool		isnew;
-	MemoryContext	tmpmem = aggstate->tmpcontext->ecxt_per_tuple_memory;
-	HeapTuple	tuple = slot->val;
-	TupleDesc	tupdesc = slot->ttc_tupleDescriptor;
-	uint32		hashkey = 0;
-	int			i;
-	int			bucketno;
-	AggHashEntry	entry;
-	MemoryContext oldContext;
-	Size		entrysize;
-
-	/* Need to run the hash function in short-lived context */
-	oldContext = MemoryContextSwitchTo(tmpmem);
-
-	for (i = 0; i < node->numCols; i++)
-	{
-		AttrNumber	att = node->grpColIdx[i];
-		Datum		attr;
-		bool		isNull;
 
-		/* rotate hashkey left 1 bit at each step */
+	entry = (AggHashEntry) LookupTupleHashEntry(aggstate->hashtable,
-		hashkey = (hashkey << 1) | ((hashkey & 0x80000000) ? 1 : 0);
+												slot,
+												&isnew);
 
-		attr = heap_getattr(tuple, att, tupdesc, &isNull);
+	if (isnew)
-		if (isNull)
-			continue;			/* treat nulls as having hash key 0 */
-		hashkey ^= ComputeHashFunc(attr,
-								   (int) tupdesc->attrs[att - 1]->attlen,
-								   tupdesc->attrs[att - 1]->attbyval);
-	}
-	bucketno = hashkey % (uint32) hashtable->nbuckets;
-
-	for (entry = hashtable->buckets[bucketno];
-		 entry != NULL;
-		 entry = entry->next)
 	{
-		/* Quick check using hashkey */
+		/* initialize aggregates for new tuple group */
-		if (entry->hashkey != hashkey)
+		initialize_aggregates(aggstate, aggstate->peragg, entry->pergroup);
-			continue;
-		if (execTuplesMatch(entry->firstTuple,
-							tuple,
-							tupdesc,
-							node->numCols, node->grpColIdx,
-							aggstate->eqfunctions,
-							tmpmem))
-		{
-			MemoryContextSwitchTo(oldContext);
-			return entry;
-		}
 	}
 
-	/* Not there, so build a new one */
-	MemoryContextSwitchTo(aggstate->aggcontext);
-	entrysize = sizeof(AggHashEntryData) +
-		(aggstate->numaggs - 1) * sizeof(AggStatePerGroupData);
-	entry = (AggHashEntry) palloc0(entrysize);
-
-	entry->hashkey = hashkey;
-	entry->firstTuple = heap_copytuple(tuple);
-
-	entry->next = hashtable->buckets[bucketno];
-	hashtable->buckets[bucketno] = entry;
-
-	MemoryContextSwitchTo(oldContext);
-
-	/* initialize aggregates for new tuple group */
-	initialize_aggregates(aggstate, aggstate->peragg, entry->pergroup);
-
 	return entry;
 }
 
@@ -964,8 +904,7 @@ agg_fill_hash_table(AggState *aggstate)
 
 	aggstate->table_filled = true;
 	/* Initialize to walk the hash table */
-	aggstate->next_hash_entry = NULL;
+	ResetTupleHashIterator(&aggstate->hashiter);
-	aggstate->next_hash_bucket = 0;
 }
 
 /*
@@ -980,7 +919,7 @@ agg_retrieve_hash_table(AggState *aggstate)
 	bool	   *aggnulls;
 	AggStatePerAgg peragg;
 	AggStatePerGroup pergroup;
-	AggHashTable	hashtable;
+	TupleHashTable	hashtable;
 	AggHashEntry	entry;
 	TupleTableSlot *firstSlot;
 	TupleTableSlot *resultSlot;
@@ -1010,18 +949,14 @@ agg_retrieve_hash_table(AggState *aggstate)
 		/*
 		 * Find the next entry in the hash table
 		 */
-		entry = aggstate->next_hash_entry;
+		entry = (AggHashEntry) ScanTupleHashTable(hashtable,
-		while (entry == NULL)
+												  &aggstate->hashiter);
+		if (entry == NULL)
 		{
-			if (aggstate->next_hash_bucket >= hashtable->nbuckets)
+			/* No more entries in hashtable, so done */
-			{
+			aggstate->agg_done = TRUE;
-				/* No more entries in hashtable, so done */
+			return NULL;
-				aggstate->agg_done = TRUE;
-				return NULL;
-			}
-			entry = hashtable->buckets[aggstate->next_hash_bucket++];
 		}
-		aggstate->next_hash_entry = entry->next;
 
 		/*
 		 * Clear the per-output-tuple context for each group
@@ -1032,7 +967,7 @@ agg_retrieve_hash_table(AggState *aggstate)
 		 * Store the copied first input tuple in the tuple table slot
 		 * reserved for it, so that it can be used in ExecProject.
 		 */
-		ExecStoreTuple(entry->firstTuple,
+		ExecStoreTuple(entry->shared.firstTuple,
 					   firstSlot,
 					   InvalidBuffer,
 					   false);
@@ -1187,6 +1122,17 @@ ExecInitAgg(Agg *node, EState *estate)
 		numaggs = 1;
 	}
 
+	/*
+	 * If we are grouping, precompute fmgr lookup data for inner loop
+	 */
+	if (node->numCols > 0)
+	{
+		aggstate->eqfunctions =
+			execTuplesMatchPrepare(ExecGetScanType(&aggstate->ss),
+								   node->numCols,
+								   node->grpColIdx);
+	}
+
 	/*
 	 * Set up aggregate-result storage in the output expr context, and also
 	 * allocate my private per-agg working storage
@@ -1211,17 +1157,6 @@ ExecInitAgg(Agg *node, EState *estate)
 		aggstate->pergroup = pergroup;
 	}
 
-	/*
-	 * If we are grouping, precompute fmgr lookup data for inner loop
-	 */
-	if (node->numCols > 0)
-	{
-		aggstate->eqfunctions =
-			execTuplesMatchPrepare(ExecGetScanType(&aggstate->ss),
-								   node->numCols,
-								   node->grpColIdx);
-	}
-
 	/*
 	 * Perform lookups of aggregate function info, and initialize the
 	 * unchanging fields of the per-agg data

src/backend/executor/nodeGroup.c

@@ -15,7 +15,7 @@
  *	  locate group boundaries.
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeGroup.c,v 1.53 2002/12/15 16:17:46 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeGroup.c,v 1.54 2003/01/10 23:54:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -23,13 +23,8 @@
 #include "postgres.h"
 
 #include "access/heapam.h"
-#include "catalog/pg_operator.h"
 #include "executor/executor.h"
 #include "executor/nodeGroup.h"
-#include "parser/parse_oper.h"
-#include "utils/builtins.h"
-#include "utils/lsyscache.h"
-#include "utils/syscache.h"
 
 
 /*
@@ -241,116 +236,3 @@ ExecReScanGroup(GroupState *node, ExprContext *exprCtxt)
 		((PlanState *) node)->lefttree->chgParam == NULL)
 		ExecReScan(((PlanState *) node)->lefttree, exprCtxt);
 }
-
-/*****************************************************************************
- *		Code shared with nodeUnique.c and nodeAgg.c
- *****************************************************************************/
-
-/*
- * execTuplesMatch
- *		Return true if two tuples match in all the indicated fields.
- *		This is used to detect group boundaries in nodeGroup and nodeAgg,
- *		and to decide whether two tuples are distinct or not in nodeUnique.
- *
- * tuple1, tuple2: the tuples to compare
- * tupdesc: tuple descriptor applying to both tuples
- * numCols: the number of attributes to be examined
- * matchColIdx: array of attribute column numbers
- * eqFunctions: array of fmgr lookup info for the equality functions to use
- * evalContext: short-term memory context for executing the functions
- *
- * NB: evalContext is reset each time!
- */
-bool
-execTuplesMatch(HeapTuple tuple1,
-				HeapTuple tuple2,
-				TupleDesc tupdesc,
-				int numCols,
-				AttrNumber *matchColIdx,
-				FmgrInfo *eqfunctions,
-				MemoryContext evalContext)
-{
-	MemoryContext oldContext;
-	bool		result;
-	int			i;
-
-	/* Reset and switch into the temp context. */
-	MemoryContextReset(evalContext);
-	oldContext = MemoryContextSwitchTo(evalContext);
-
-	/*
-	 * We cannot report a match without checking all the fields, but we
-	 * can report a non-match as soon as we find unequal fields.  So,
-	 * start comparing at the last field (least significant sort key).
-	 * That's the most likely to be different if we are dealing with
-	 * sorted input.
-	 */
-	result = true;
-
-	for (i = numCols; --i >= 0;)
-	{
-		AttrNumber	att = matchColIdx[i];
-		Datum		attr1,
-					attr2;
-		bool		isNull1,
-					isNull2;
-
-		attr1 = heap_getattr(tuple1,
-							 att,
-							 tupdesc,
-							 &isNull1);
-
-		attr2 = heap_getattr(tuple2,
-							 att,
-							 tupdesc,
-							 &isNull2);
-
-		if (isNull1 != isNull2)
-		{
-			result = false;		/* one null and one not; they aren't equal */
-			break;
-		}
-
-		if (isNull1)
-			continue;			/* both are null, treat as equal */
-
-		/* Apply the type-specific equality function */
-
-		if (!DatumGetBool(FunctionCall2(&eqfunctions[i],
-										attr1, attr2)))
-		{
-			result = false;		/* they aren't equal */
-			break;
-		}
-	}
-
-	MemoryContextSwitchTo(oldContext);
-
-	return result;
-}
-
-/*
- * execTuplesMatchPrepare
- *		Look up the equality functions needed for execTuplesMatch.
- *		The result is a palloc'd array.
- */
-FmgrInfo *
-execTuplesMatchPrepare(TupleDesc tupdesc,
-					   int numCols,
-					   AttrNumber *matchColIdx)
-{
-	FmgrInfo   *eqfunctions = (FmgrInfo *) palloc(numCols * sizeof(FmgrInfo));
-	int			i;
-
-	for (i = 0; i < numCols; i++)
-	{
-		AttrNumber	att = matchColIdx[i];
-		Oid			typid = tupdesc->attrs[att - 1]->atttypid;
-		Oid			eq_function;
-
-		eq_function = equality_oper_funcid(typid);
-		fmgr_info(eq_function, &eqfunctions[i]);
-	}
-
-	return eqfunctions;
-}

src/backend/executor/nodeHash.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeHash.c,v 1.73 2002/12/30 15:21:18 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeHash.c,v 1.74 2003/01/10 23:54:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -20,10 +20,6 @@
  */
 #include "postgres.h"
 
-#include <limits.h>
-#include <math.h>
-
-#include "access/hash.h"
 #include "executor/execdebug.h"
 #include "executor/nodeHash.h"
 #include "executor/nodeHashjoin.h"
@@ -642,74 +638,6 @@ ExecScanHashBucket(HashJoinState *hjstate,
 	return NULL;
 }
 
-/* ----------------------------------------------------------------
- *		ComputeHashFunc
- *
- *		the hash function for hash joins (also used for hash aggregation)
- *
- *		XXX this probably ought to be replaced with datatype-specific
- *		hash functions, such as those already implemented for hash indexes.
- * ----------------------------------------------------------------
- */
-uint32
-ComputeHashFunc(Datum key, int typLen, bool byVal)
-{
-	unsigned char *k;
-
-	if (byVal)
-	{
-		/*
-		 * If it's a by-value data type, just hash the whole Datum value.
-		 * This assumes that datatypes narrower than Datum are
-		 * consistently padded (either zero-extended or sign-extended, but
-		 * not random bits) to fill Datum; see the XXXGetDatum macros in
-		 * postgres.h. NOTE: it would not work to do hash_any(&key, len)
-		 * since this would get the wrong bytes on a big-endian machine.
-		 */
-		k = (unsigned char *) &key;
-		typLen = sizeof(Datum);
-	}
-	else
-	{
-		if (typLen > 0)
-		{
-			/* fixed-width pass-by-reference type */
-			k = (unsigned char *) DatumGetPointer(key);
-		}
-		else if (typLen == -1)
-		{
-			/*
-			 * It's a varlena type, so 'key' points to a "struct varlena".
-			 * NOTE: VARSIZE returns the "real" data length plus the
-			 * sizeof the "vl_len" attribute of varlena (the length
-			 * information). 'key' points to the beginning of the varlena
-			 * struct, so we have to use "VARDATA" to find the beginning
-			 * of the "real" data.	Also, we have to be careful to detoast
-			 * the datum if it's toasted.  (We don't worry about freeing
-			 * the detoasted copy; that happens for free when the
-			 * per-tuple memory context is reset in ExecHashGetBucket.)
-			 */
-			struct varlena *vkey = PG_DETOAST_DATUM(key);
-
-			typLen = VARSIZE(vkey) - VARHDRSZ;
-			k = (unsigned char *) VARDATA(vkey);
-		}
-		else if (typLen == -2)
-		{
-			/* It's a null-terminated C string */
-			typLen = strlen(DatumGetCString(key)) + 1;
-			k = (unsigned char *) DatumGetPointer(key);
-		}
-		else
-		{
-			elog(ERROR, "ComputeHashFunc: Invalid typLen %d", typLen);
-			k = NULL;			/* keep compiler quiet */
-		}
-	}
-
-	return DatumGetUInt32(hash_any(k, typLen));
-}
-
 /* ----------------------------------------------------------------
  *		ExecHashTableReset
  *

src/backend/executor/nodeSetOp.c

@@ -21,7 +21,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSetOp.c,v 1.8 2002/12/15 16:17:46 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSetOp.c,v 1.9 2003/01/10 23:54:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -36,9 +36,9 @@
 
 #include "access/heapam.h"
 #include "executor/executor.h"
-#include "executor/nodeGroup.h"
 #include "executor/nodeSetOp.h"
 
+
 /* ----------------------------------------------------------------
  *		ExecSetOp
  * ----------------------------------------------------------------

src/backend/executor/nodeUnique.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeUnique.c,v 1.36 2002/12/15 16:17:46 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeUnique.c,v 1.37 2003/01/10 23:54:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -27,9 +27,9 @@
 
 #include "access/heapam.h"
 #include "executor/executor.h"
-#include "executor/nodeGroup.h"
 #include "executor/nodeUnique.h"
 
+
 /* ----------------------------------------------------------------
  *		ExecUnique
  *

src/include/executor/executor.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: executor.h,v 1.85 2002/12/15 21:01:34 tgl Exp $
+ * $Id: executor.h,v 1.86 2003/01/10 23:54:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -36,6 +36,31 @@ extern void ExecMarkPos(PlanState *node);
 extern void ExecRestrPos(PlanState *node);
 extern bool ExecSupportsMarkRestore(NodeTag plantype);
 
+/*
+ * prototypes from functions in execGrouping.c
+ */
+extern bool execTuplesMatch(HeapTuple tuple1,
+				HeapTuple tuple2,
+				TupleDesc tupdesc,
+				int numCols,
+				AttrNumber *matchColIdx,
+				FmgrInfo *eqfunctions,
+				MemoryContext evalContext);
+extern FmgrInfo *execTuplesMatchPrepare(TupleDesc tupdesc,
+					   int numCols,
+					   AttrNumber *matchColIdx);
+extern uint32 ComputeHashFunc(Datum key, int typLen, bool byVal);
+extern TupleHashTable BuildTupleHashTable(int numCols, AttrNumber *keyColIdx,
+										  FmgrInfo *eqfunctions,
+										  int nbuckets, Size entrysize,
+										  MemoryContext tablecxt,
+										  MemoryContext tempcxt);
+extern TupleHashEntry LookupTupleHashEntry(TupleHashTable hashtable,
+										   TupleTableSlot *slot,
+										   bool *isnew);
+extern TupleHashEntry ScanTupleHashTable(TupleHashTable hashtable,
+										 TupleHashIterator *state);
+
 /*
  * prototypes from functions in execJunk.c
  */

src/include/executor/nodeAgg.h

@@ -1,13 +1,13 @@
 /*-------------------------------------------------------------------------
  *
  * nodeAgg.h
- *
+ *	  prototypes for nodeAgg.c
  *
  *
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nodeAgg.h,v 1.18 2002/12/05 15:50:36 tgl Exp $
+ * $Id: nodeAgg.h,v 1.19 2003/01/10 23:54:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */

src/include/executor/nodeGroup.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: nodeGroup.h,v 1.23 2002/12/05 15:50:37 tgl Exp $
+ * $Id: nodeGroup.h,v 1.24 2003/01/10 23:54:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,15 +22,4 @@ extern TupleTableSlot *ExecGroup(GroupState *node);
 extern void ExecEndGroup(GroupState *node);
 extern void ExecReScanGroup(GroupState *node, ExprContext *exprCtxt);
 
-extern bool execTuplesMatch(HeapTuple tuple1,
-				HeapTuple tuple2,
-				TupleDesc tupdesc,
-				int numCols,
-				AttrNumber *matchColIdx,
-				FmgrInfo *eqfunctions,
-				MemoryContext evalContext);
-extern FmgrInfo *execTuplesMatchPrepare(TupleDesc tupdesc,
-					   int numCols,
-					   AttrNumber *matchColIdx);
-
 #endif   /* NODEGROUP_H */

src/include/executor/nodeHash.h

@@ -1,13 +1,13 @@
 /*-------------------------------------------------------------------------
  *
  * nodeHash.h
- *
+ *	  prototypes for nodeHash.c
  *
  *
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nodeHash.h,v 1.28 2002/12/30 15:21:23 tgl Exp $
+ * $Id: nodeHash.h,v 1.29 2003/01/10 23:54:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -38,6 +38,5 @@ extern void ExecChooseHashTableSize(double ntuples, int tupwidth,
 						int *virtualbuckets,
 						int *physicalbuckets,
 						int *numbatches);
-extern uint32 ComputeHashFunc(Datum key, int typLen, bool byVal);
 
 #endif   /* NODEHASH_H */

src/include/nodes/execnodes.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: execnodes.h,v 1.89 2003/01/10 21:08:15 tgl Exp $
+ * $Id: execnodes.h,v 1.90 2003/01/10 23:54:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -324,6 +324,46 @@ typedef struct EState
 } EState;
 
 
+/* ----------------------------------------------------------------
+ *				 Tuple Hash Tables
+ *
+ * All-in-memory tuple hash tables are used for a number of purposes.
+ * ----------------------------------------------------------------
+ */
+typedef struct TupleHashEntryData *TupleHashEntry;
+typedef struct TupleHashTableData *TupleHashTable;
+
+typedef struct TupleHashEntryData
+{
+	TupleHashEntry next;		/* next entry in same hash bucket */
+	uint32		hashkey;		/* exact hash key of this entry */
+	HeapTuple	firstTuple;		/* copy of first tuple in this group */
+	/* there may be additional data beyond the end of this struct */
+} TupleHashEntryData;			/* VARIABLE LENGTH STRUCT */
+
+typedef struct TupleHashTableData
+{
+	int			numCols;		/* number of columns in lookup key */
+	AttrNumber *keyColIdx;		/* attr numbers of key columns */
+	FmgrInfo   *eqfunctions;	/* lookup data for comparison functions */
+	MemoryContext tablecxt;		/* memory context containing table */
+	MemoryContext tempcxt;		/* context for function evaluations */
+	Size		entrysize;		/* actual size to make each hash entry */
+	int			nbuckets;		/* number of buckets in hash table */
+	TupleHashEntry buckets[1];	/* VARIABLE LENGTH ARRAY */
+} TupleHashTableData;			/* VARIABLE LENGTH STRUCT */
+
+typedef struct
+{
+	TupleHashEntry next_entry;	/* next entry in current chain */
+	int			next_bucket;	/* next chain */
+} TupleHashIterator;
+
+#define ResetTupleHashIterator(iter) \
+	((iter)->next_entry = NULL, \
+	 (iter)->next_bucket = 0)
+
+
 /* ----------------------------------------------------------------
  *				 Expression State Trees
  *
@@ -445,9 +485,6 @@ typedef struct BoolExprState
  *		SubPlanState node
  * ----------------
  */
-/* this struct is private in nodeSubplan.c: */
-typedef struct SubPlanHashTableData *SubPlanHashTable;
-
 typedef struct SubPlanState
 {
 	ExprState	xprstate;
@@ -458,8 +495,8 @@ typedef struct SubPlanState
 	bool		needShutdown;	/* TRUE = need to shutdown subplan */
 	HeapTuple	curTuple;		/* copy of most recent tuple from subplan */
 	/* these are used when hashing the subselect's output: */
-	SubPlanHashTable hashtable;	/* hash table for no-nulls subselect rows */
+	TupleHashTable hashtable;	/* hash table for no-nulls subselect rows */
-	SubPlanHashTable hashnulls;	/* hash table for rows with null(s) */
+	TupleHashTable hashnulls;	/* hash table for rows with null(s) */
 } SubPlanState;
 
 /* ----------------
@@ -877,8 +914,6 @@ typedef struct GroupState
 /* these structs are private in nodeAgg.c: */
 typedef struct AggStatePerAggData *AggStatePerAgg;
 typedef struct AggStatePerGroupData *AggStatePerGroup;
-typedef struct AggHashEntryData *AggHashEntry;
-typedef struct AggHashTableData *AggHashTable;
 
 typedef struct AggState
 {
@@ -894,10 +929,9 @@ typedef struct AggState
 	AggStatePerGroup pergroup;	/* per-Aggref-per-group working state */
 	HeapTuple	grp_firstTuple;	/* copy of first tuple of current group */
 	/* these fields are used in AGG_HASHED mode: */
-	AggHashTable hashtable;		/* hash table with one entry per group */
+	TupleHashTable hashtable;	/* hash table with one entry per group */
 	bool		table_filled;	/* hash table filled yet? */
-	AggHashEntry next_hash_entry; /* next entry in current chain */
+	TupleHashIterator hashiter;	/* for iterating through hash table */
-	int			next_hash_bucket; /* next chain */
 } AggState;
 
 /* ----------------