Change the name of the Result Cache node to Memoize

"Result Cache" was never a great name for this node, but nobody managed
to come up with another name that anyone liked enough.  That was until
David Johnston mentioned "Node Memoization", which Tom Lane revised to
just "Memoize".  People seem to like "Memoize", so let's do the rename.

Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/20210708165145.GG1176@momjian.us
Backpatch-through: 14, where Result Cache was introduced

contrib/postgres_fdw/expected/postgres_fdw.out

@@ -1602,7 +1602,7 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL
  20 |  0 | AAA020
 (10 rows)
 
-SET enable_resultcache TO off;
+SET enable_memoize TO off;
 -- right outer join + left outer join
 EXPLAIN (VERBOSE, COSTS OFF)
 SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
@@ -1629,7 +1629,7 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT
  20 |  0 | AAA020
 (10 rows)
 
-RESET enable_resultcache;
+RESET enable_memoize;
 -- left outer join + right outer join
 EXPLAIN (VERBOSE, COSTS OFF)
 SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
@@ -2149,7 +2149,7 @@ SELECT t1."C 1" FROM "S 1"."T 1" t1, LATERAL (SELECT DISTINCT t2.c1, t3.c1 FROM
          Output: t1."C 1"
          ->  Index Scan using t1_pkey on "S 1"."T 1" t1
                Output: t1."C 1", t1.c2, t1.c3, t1.c4, t1.c5, t1.c6, t1.c7, t1.c8
-         ->  Result Cache
+         ->  Memoize
                Cache Key: t1.c2
                ->  Subquery Scan on q
                      ->  HashAggregate

contrib/postgres_fdw/sql/postgres_fdw.sql

@@ -502,12 +502,12 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT
 EXPLAIN (VERBOSE, COSTS OFF)
 SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
 SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-SET enable_resultcache TO off;
+SET enable_memoize TO off;
 -- right outer join + left outer join
 EXPLAIN (VERBOSE, COSTS OFF)
 SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
 SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-RESET enable_resultcache;
+RESET enable_memoize;
 -- left outer join + right outer join
 EXPLAIN (VERBOSE, COSTS OFF)
 SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;

doc/src/sgml/config.sgml

@@ -5014,15 +5014,15 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
       </listitem>
      </varlistentry>
 
-     <varlistentry id="guc-enable-resultcache" xreflabel="enable_resultcache">
-      <term><varname>enable_resultcache</varname> (<type>boolean</type>)
+     <varlistentry id="guc-enable-memoize" xreflabel="enable_memoize">
+      <term><varname>enable_memoize</varname> (<type>boolean</type>)
       <indexterm>
-       <primary><varname>enable_resultcache</varname> configuration parameter</primary>
+       <primary><varname>enable_memoize</varname> configuration parameter</primary>
       </indexterm>
       </term>
       <listitem>
        <para>
-        Enables or disables the query planner's use of result cache plans for
+        Enables or disables the query planner's use of memoize plans for
         caching results from parameterized scans inside nested-loop joins.
         This plan type allows scans to the underlying plans to be skipped when
         the results for the current parameters are already in the cache.  Less

doc/src/sgml/release-14.sgml

@@ -1191,7 +1191,7 @@ Author: David Rowley <drowley@postgresql.org>
        <para>
         This is useful if only a small percentage of rows is checked on
         the inner side and is controlled by <xref
-        linkend="guc-enable-resultcache"/>.
+        linkend="guc-enable-memoize"/>.
        </para>
       </listitem>
 

src/backend/commands/explain.c

@@ -109,8 +109,8 @@ static void show_sort_info(SortState *sortstate, ExplainState *es);
 static void show_incremental_sort_info(IncrementalSortState *incrsortstate,
 									   ExplainState *es);
 static void show_hash_info(HashState *hashstate, ExplainState *es);
-static void show_resultcache_info(ResultCacheState *rcstate, List *ancestors,
-								  ExplainState *es);
+static void show_memoize_info(MemoizeState *mstate, List *ancestors,
+							  ExplainState *es);
 static void show_hashagg_info(AggState *hashstate, ExplainState *es);
 static void show_tidbitmap_info(BitmapHeapScanState *planstate,
 								ExplainState *es);
@@ -1298,8 +1298,8 @@ ExplainNode(PlanState *planstate, List *ancestors,
 		case T_Material:
 			pname = sname = "Materialize";
 			break;
-		case T_ResultCache:
-			pname = sname = "Result Cache";
+		case T_Memoize:
+			pname = sname = "Memoize";
 			break;
 		case T_Sort:
 			pname = sname = "Sort";
@@ -2013,9 +2013,9 @@ ExplainNode(PlanState *planstate, List *ancestors,
 		case T_Hash:
 			show_hash_info(castNode(HashState, planstate), es);
 			break;
-		case T_ResultCache:
-			show_resultcache_info(castNode(ResultCacheState, planstate),
-								  ancestors, es);
+		case T_Memoize:
+			show_memoize_info(castNode(MemoizeState, planstate), ancestors,
+							  es);
 			break;
 		default:
 			break;
@@ -3085,13 +3085,12 @@ show_hash_info(HashState *hashstate, ExplainState *es)
 }
 
 /*
- * Show information on result cache hits/misses/evictions and memory usage.
+ * Show information on memoize hits/misses/evictions and memory usage.
  */
 static void
-show_resultcache_info(ResultCacheState *rcstate, List *ancestors,
-					  ExplainState *es)
+show_memoize_info(MemoizeState *mstate, List *ancestors, ExplainState *es)
 {
-	Plan	   *plan = ((PlanState *) rcstate)->plan;
+	Plan	   *plan = ((PlanState *) mstate)->plan;
 	ListCell   *lc;
 	List	   *context;
 	StringInfoData keystr;
@@ -3102,7 +3101,7 @@ show_resultcache_info(ResultCacheState *rcstate, List *ancestors,
 	initStringInfo(&keystr);
 
 	/*
-	 * It's hard to imagine having a result cache with fewer than 2 RTEs, but
+	 * It's hard to imagine having a memoize node with fewer than 2 RTEs, but
 	 * let's just keep the same useprefix logic as elsewhere in this file.
 	 */
 	useprefix = list_length(es->rtable) > 1 || es->verbose;
@@ -3112,7 +3111,7 @@ show_resultcache_info(ResultCacheState *rcstate, List *ancestors,
 									   plan,
 									   ancestors);
 
-	foreach(lc, ((ResultCache *) plan)->param_exprs)
+	foreach(lc, ((Memoize *) plan)->param_exprs)
 	{
 		Node	   *expr = (Node *) lfirst(lc);
 
@@ -3138,23 +3137,23 @@ show_resultcache_info(ResultCacheState *rcstate, List *ancestors,
 	if (!es->analyze)
 		return;
 
-	if (rcstate->stats.cache_misses > 0)
+	if (mstate->stats.cache_misses > 0)
 	{
 		/*
 		 * mem_peak is only set when we freed memory, so we must use mem_used
 		 * when mem_peak is 0.
 		 */
-		if (rcstate->stats.mem_peak > 0)
-			memPeakKb = (rcstate->stats.mem_peak + 1023) / 1024;
+		if (mstate->stats.mem_peak > 0)
+			memPeakKb = (mstate->stats.mem_peak + 1023) / 1024;
 		else
-			memPeakKb = (rcstate->mem_used + 1023) / 1024;
+			memPeakKb = (mstate->mem_used + 1023) / 1024;
 
 		if (es->format != EXPLAIN_FORMAT_TEXT)
 		{
-			ExplainPropertyInteger("Cache Hits", NULL, rcstate->stats.cache_hits, es);
-			ExplainPropertyInteger("Cache Misses", NULL, rcstate->stats.cache_misses, es);
-			ExplainPropertyInteger("Cache Evictions", NULL, rcstate->stats.cache_evictions, es);
-			ExplainPropertyInteger("Cache Overflows", NULL, rcstate->stats.cache_overflows, es);
+			ExplainPropertyInteger("Cache Hits", NULL, mstate->stats.cache_hits, es);
+			ExplainPropertyInteger("Cache Misses", NULL, mstate->stats.cache_misses, es);
+			ExplainPropertyInteger("Cache Evictions", NULL, mstate->stats.cache_evictions, es);
+			ExplainPropertyInteger("Cache Overflows", NULL, mstate->stats.cache_overflows, es);
 			ExplainPropertyInteger("Peak Memory Usage", "kB", memPeakKb, es);
 		}
 		else
@@ -3162,23 +3161,23 @@ show_resultcache_info(ResultCacheState *rcstate, List *ancestors,
 			ExplainIndentText(es);
 			appendStringInfo(es->str,
 							 "Hits: " UINT64_FORMAT "  Misses: " UINT64_FORMAT "  Evictions: " UINT64_FORMAT "  Overflows: " UINT64_FORMAT "  Memory Usage: " INT64_FORMAT "kB\n",
-							 rcstate->stats.cache_hits,
-							 rcstate->stats.cache_misses,
-							 rcstate->stats.cache_evictions,
-							 rcstate->stats.cache_overflows,
+							 mstate->stats.cache_hits,
+							 mstate->stats.cache_misses,
+							 mstate->stats.cache_evictions,
+							 mstate->stats.cache_overflows,
 							 memPeakKb);
 		}
 	}
 
-	if (rcstate->shared_info == NULL)
+	if (mstate->shared_info == NULL)
 		return;
 
 	/* Show details from parallel workers */
-	for (int n = 0; n < rcstate->shared_info->num_workers; n++)
+	for (int n = 0; n < mstate->shared_info->num_workers; n++)
 	{
-		ResultCacheInstrumentation *si;
+		MemoizeInstrumentation *si;
 
-		si = &rcstate->shared_info->sinstrument[n];
+		si = &mstate->shared_info->sinstrument[n];
 
 		/*
 		 * Skip workers that didn't do any work.  We needn't bother checking
@@ -3191,10 +3190,10 @@ show_resultcache_info(ResultCacheState *rcstate, List *ancestors,
 			ExplainOpenWorker(n, es);
 
 		/*
-		 * Since the worker's ResultCacheState.mem_used field is unavailable
-		 * to us, ExecEndResultCache will have set the
-		 * ResultCacheInstrumentation.mem_peak field for us.  No need to do
-		 * the zero checks like we did for the serial case above.
+		 * Since the worker's MemoizeState.mem_used field is unavailable to
+		 * us, ExecEndMemoize will have set the
+		 * MemoizeInstrumentation.mem_peak field for us.  No need to do the
+		 * zero checks like we did for the serial case above.
 		 */
 		memPeakKb = (si->mem_peak + 1023) / 1024;
 

src/backend/executor/Makefile

@@ -53,6 +53,7 @@ OBJS = \
 	nodeLimit.o \
 	nodeLockRows.o \
 	nodeMaterial.o \
+	nodeMemoize.o \
 	nodeMergeAppend.o \
 	nodeMergejoin.o \
 	nodeModifyTable.o \
@@ -61,7 +62,6 @@ OBJS = \
 	nodeProjectSet.o \
 	nodeRecursiveunion.o \
 	nodeResult.o \
-	nodeResultCache.o \
 	nodeSamplescan.o \
 	nodeSeqscan.o \
 	nodeSetOp.o \

src/backend/executor/execAmi.c

@@ -36,6 +36,7 @@
 #include "executor/nodeLimit.h"
 #include "executor/nodeLockRows.h"
 #include "executor/nodeMaterial.h"
+#include "executor/nodeMemoize.h"
 #include "executor/nodeMergeAppend.h"
 #include "executor/nodeMergejoin.h"
 #include "executor/nodeModifyTable.h"
@@ -44,7 +45,6 @@
 #include "executor/nodeProjectSet.h"
 #include "executor/nodeRecursiveunion.h"
 #include "executor/nodeResult.h"
-#include "executor/nodeResultCache.h"
 #include "executor/nodeSamplescan.h"
 #include "executor/nodeSeqscan.h"
 #include "executor/nodeSetOp.h"
@@ -255,8 +255,8 @@ ExecReScan(PlanState *node)
 			ExecReScanMaterial((MaterialState *) node);
 			break;
 
-		case T_ResultCacheState:
-			ExecReScanResultCache((ResultCacheState *) node);
+		case T_MemoizeState:
+			ExecReScanMemoize((MemoizeState *) node);
 			break;
 
 		case T_SortState:

src/backend/executor/execParallel.c

@@ -35,7 +35,7 @@
 #include "executor/nodeIncrementalSort.h"
 #include "executor/nodeIndexonlyscan.h"
 #include "executor/nodeIndexscan.h"
-#include "executor/nodeResultCache.h"
+#include "executor/nodeMemoize.h"
 #include "executor/nodeSeqscan.h"
 #include "executor/nodeSort.h"
 #include "executor/nodeSubplan.h"
@@ -293,9 +293,9 @@ ExecParallelEstimate(PlanState *planstate, ExecParallelEstimateContext *e)
 			/* even when not parallel-aware, for EXPLAIN ANALYZE */
 			ExecAggEstimate((AggState *) planstate, e->pcxt);
 			break;
-		case T_ResultCacheState:
+		case T_MemoizeState:
 			/* even when not parallel-aware, for EXPLAIN ANALYZE */
-			ExecResultCacheEstimate((ResultCacheState *) planstate, e->pcxt);
+			ExecMemoizeEstimate((MemoizeState *) planstate, e->pcxt);
 			break;
 		default:
 			break;
@@ -517,9 +517,9 @@ ExecParallelInitializeDSM(PlanState *planstate,
 			/* even when not parallel-aware, for EXPLAIN ANALYZE */
 			ExecAggInitializeDSM((AggState *) planstate, d->pcxt);
 			break;
-		case T_ResultCacheState:
+		case T_MemoizeState:
 			/* even when not parallel-aware, for EXPLAIN ANALYZE */
-			ExecResultCacheInitializeDSM((ResultCacheState *) planstate, d->pcxt);
+			ExecMemoizeInitializeDSM((MemoizeState *) planstate, d->pcxt);
 			break;
 		default:
 			break;
@@ -997,7 +997,7 @@ ExecParallelReInitializeDSM(PlanState *planstate,
 		case T_HashState:
 		case T_SortState:
 		case T_IncrementalSortState:
-		case T_ResultCacheState:
+		case T_MemoizeState:
 			/* these nodes have DSM state, but no reinitialization is required */
 			break;
 
@@ -1067,8 +1067,8 @@ ExecParallelRetrieveInstrumentation(PlanState *planstate,
 		case T_AggState:
 			ExecAggRetrieveInstrumentation((AggState *) planstate);
 			break;
-		case T_ResultCacheState:
-			ExecResultCacheRetrieveInstrumentation((ResultCacheState *) planstate);
+		case T_MemoizeState:
+			ExecMemoizeRetrieveInstrumentation((MemoizeState *) planstate);
 			break;
 		default:
 			break;
@@ -1362,10 +1362,9 @@ ExecParallelInitializeWorker(PlanState *planstate, ParallelWorkerContext *pwcxt)
 			/* even when not parallel-aware, for EXPLAIN ANALYZE */
 			ExecAggInitializeWorker((AggState *) planstate, pwcxt);
 			break;
-		case T_ResultCacheState:
+		case T_MemoizeState:
 			/* even when not parallel-aware, for EXPLAIN ANALYZE */
-			ExecResultCacheInitializeWorker((ResultCacheState *) planstate,
-											pwcxt);
+			ExecMemoizeInitializeWorker((MemoizeState *) planstate, pwcxt);
 			break;
 		default:
 			break;

src/backend/executor/execProcnode.c

@@ -94,6 +94,7 @@
 #include "executor/nodeLimit.h"
 #include "executor/nodeLockRows.h"
 #include "executor/nodeMaterial.h"
+#include "executor/nodeMemoize.h"
 #include "executor/nodeMergeAppend.h"
 #include "executor/nodeMergejoin.h"
 #include "executor/nodeModifyTable.h"
@@ -102,7 +103,6 @@
 #include "executor/nodeProjectSet.h"
 #include "executor/nodeRecursiveunion.h"
 #include "executor/nodeResult.h"
-#include "executor/nodeResultCache.h"
 #include "executor/nodeSamplescan.h"
 #include "executor/nodeSeqscan.h"
 #include "executor/nodeSetOp.h"
@@ -326,9 +326,9 @@ ExecInitNode(Plan *node, EState *estate, int eflags)
 														   estate, eflags);
 			break;
 
-		case T_ResultCache:
-			result = (PlanState *) ExecInitResultCache((ResultCache *) node,
-													   estate, eflags);
+		case T_Memoize:
+			result = (PlanState *) ExecInitMemoize((Memoize *) node, estate,
+												   eflags);
 			break;
 
 		case T_Group:
@@ -720,8 +720,8 @@ ExecEndNode(PlanState *node)
 			ExecEndIncrementalSort((IncrementalSortState *) node);
 			break;
 
-		case T_ResultCacheState:
-			ExecEndResultCache((ResultCacheState *) node);
+		case T_MemoizeState:
+			ExecEndMemoize((MemoizeState *) node);
 			break;
 
 		case T_GroupState:

src/backend/nodes/copyfuncs.c

@@ -950,12 +950,12 @@ _copyMaterial(const Material *from)
 
 
 /*
- * _copyResultCache
+ * _copyMemoize
  */
-static ResultCache *
-_copyResultCache(const ResultCache *from)
+static Memoize *
+_copyMemoize(const Memoize *from)
 {
-	ResultCache *newnode = makeNode(ResultCache);
+	Memoize    *newnode = makeNode(Memoize);
 
 	/*
 	 * copy node superclass fields
@@ -5078,8 +5078,8 @@ copyObjectImpl(const void *from)
 		case T_Material:
 			retval = _copyMaterial(from);
 			break;
-		case T_ResultCache:
-			retval = _copyResultCache(from);
+		case T_Memoize:
+			retval = _copyMemoize(from);
 			break;
 		case T_Sort:
 			retval = _copySort(from);

src/backend/nodes/outfuncs.c

@@ -848,9 +848,9 @@ _outMaterial(StringInfo str, const Material *node)
 }
 
 static void
-_outResultCache(StringInfo str, const ResultCache *node)
+_outMemoize(StringInfo str, const Memoize *node)
 {
-	WRITE_NODE_TYPE("RESULTCACHE");
+	WRITE_NODE_TYPE("MEMOIZE");
 
 	_outPlanInfo(str, (const Plan *) node);
 
@@ -1948,9 +1948,9 @@ _outMaterialPath(StringInfo str, const MaterialPath *node)
 }
 
 static void
-_outResultCachePath(StringInfo str, const ResultCachePath *node)
+_outMemoizePath(StringInfo str, const MemoizePath *node)
 {
-	WRITE_NODE_TYPE("RESULTCACHEPATH");
+	WRITE_NODE_TYPE("MEMOIZEPATH");
 
 	_outPathInfo(str, (const Path *) node);
 
@@ -3960,8 +3960,8 @@ outNode(StringInfo str, const void *obj)
 			case T_Material:
 				_outMaterial(str, obj);
 				break;
-			case T_ResultCache:
-				_outResultCache(str, obj);
+			case T_Memoize:
+				_outMemoize(str, obj);
 				break;
 			case T_Sort:
 				_outSort(str, obj);
@@ -4200,8 +4200,8 @@ outNode(StringInfo str, const void *obj)
 			case T_MaterialPath:
 				_outMaterialPath(str, obj);
 				break;
-			case T_ResultCachePath:
-				_outResultCachePath(str, obj);
+			case T_MemoizePath:
+				_outMemoizePath(str, obj);
 				break;
 			case T_UniquePath:
 				_outUniquePath(str, obj);

src/backend/nodes/readfuncs.c

@@ -2215,12 +2215,12 @@ _readMaterial(void)
 }
 
 /*
- * _readResultCache
+ * _readMemoize
  */
-static ResultCache *
-_readResultCache(void)
+static Memoize *
+_readMemoize(void)
 {
-	READ_LOCALS(ResultCache);
+	READ_LOCALS(Memoize);
 
 	ReadCommonPlan(&local_node->plan);
 
@@ -2922,8 +2922,8 @@ parseNodeString(void)
 		return_value = _readHashJoin();
 	else if (MATCH("MATERIAL", 8))
 		return_value = _readMaterial();
-	else if (MATCH("RESULTCACHE", 11))
-		return_value = _readResultCache();
+	else if (MATCH("MEMOIZE", 7))
+		return_value = _readMemoize();
 	else if (MATCH("SORT", 4))
 		return_value = _readSort();
 	else if (MATCH("INCREMENTALSORT", 15))

src/backend/optimizer/README

@@ -382,7 +382,7 @@ RelOptInfo      - a relation or joined relations
   MergeAppendPath - merge multiple subpaths, preserving their common sort order
   GroupResultPath - childless Result plan node (used for degenerate grouping)
   MaterialPath  - a Material plan node
-  ResultCachePath - a result cache plan node for caching tuples from sub-paths
+  MemoizePath   - a Memoize plan node for caching tuples from sub-paths
   UniquePath    - remove duplicate rows (either by hashing or sorting)
   GatherPath    - collect the results of parallel workers
   GatherMergePath - collect parallel results, preserving their common sort order

src/backend/optimizer/path/allpaths.c

@@ -4031,9 +4031,9 @@ print_path(PlannerInfo *root, Path *path, int indent)
 			ptype = "Material";
 			subpath = ((MaterialPath *) path)->subpath;
 			break;
-		case T_ResultCachePath:
-			ptype = "ResultCache";
-			subpath = ((ResultCachePath *) path)->subpath;
+		case T_MemoizePath:
+			ptype = "Memoize";
+			subpath = ((MemoizePath *) path)->subpath;
 			break;
 		case T_UniquePath:
 			ptype = "Unique";

src/backend/optimizer/path/costsize.c

@@ -79,7 +79,7 @@
 #include "executor/executor.h"
 #include "executor/nodeAgg.h"
 #include "executor/nodeHash.h"
-#include "executor/nodeResultCache.h"
+#include "executor/nodeMemoize.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
@@ -140,7 +140,7 @@ bool		enable_incremental_sort = true;
 bool		enable_hashagg = true;
 bool		enable_nestloop = true;
 bool		enable_material = true;
-bool		enable_resultcache = true;
+bool		enable_memoize = true;
 bool		enable_mergejoin = true;
 bool		enable_hashjoin = true;
 bool		enable_gathermerge = true;
@@ -2405,8 +2405,8 @@ cost_material(Path *path,
 }
 
 /*
- * cost_resultcache_rescan
- *	  Determines the estimated cost of rescanning a ResultCache node.
+ * cost_memoize_rescan
+ *	  Determines the estimated cost of rescanning a Memoize node.
  *
  * In order to estimate this, we must gain knowledge of how often we expect to
  * be called and how many distinct sets of parameters we are likely to be
@@ -2418,15 +2418,15 @@ cost_material(Path *path,
  * hit and caching would be a complete waste of effort.
  */
 static void
-cost_resultcache_rescan(PlannerInfo *root, ResultCachePath *rcpath,
-						Cost *rescan_startup_cost, Cost *rescan_total_cost)
+cost_memoize_rescan(PlannerInfo *root, MemoizePath *mpath,
+					Cost *rescan_startup_cost, Cost *rescan_total_cost)
 {
 	EstimationInfo estinfo;
-	Cost		input_startup_cost = rcpath->subpath->startup_cost;
-	Cost		input_total_cost = rcpath->subpath->total_cost;
-	double		tuples = rcpath->subpath->rows;
-	double		calls = rcpath->calls;
-	int			width = rcpath->subpath->pathtarget->width;
+	Cost		input_startup_cost = mpath->subpath->startup_cost;
+	Cost		input_total_cost = mpath->subpath->total_cost;
+	double		tuples = mpath->subpath->rows;
+	double		calls = mpath->calls;
+	int			width = mpath->subpath->pathtarget->width;
 
 	double		hash_mem_bytes;
 	double		est_entry_bytes;
@@ -2455,16 +2455,16 @@ cost_resultcache_rescan(PlannerInfo *root, ResultCachePath *rcpath,
 	est_cache_entries = floor(hash_mem_bytes / est_entry_bytes);
 
 	/* estimate on the distinct number of parameter values */
-	ndistinct = estimate_num_groups(root, rcpath->param_exprs, calls, NULL,
+	ndistinct = estimate_num_groups(root, mpath->param_exprs, calls, NULL,
 									&estinfo);
 
 	/*
 	 * When the estimation fell back on using a default value, it's a bit too
-	 * risky to assume that it's ok to use a Result Cache.  The use of a
-	 * default could cause us to use a Result Cache when it's really
+	 * risky to assume that it's ok to use a Memoize node.  The use of a
+	 * default could cause us to use a Memoize node when it's really
 	 * inappropriate to do so.  If we see that this has been done, then we'll
 	 * assume that every call will have unique parameters, which will almost
-	 * certainly mean a ResultCachePath will never survive add_path().
+	 * certainly mean a MemoizePath will never survive add_path().
 	 */
 	if ((estinfo.flags & SELFLAG_USED_DEFAULT) != 0)
 		ndistinct = calls;
@@ -2478,8 +2478,8 @@ cost_resultcache_rescan(PlannerInfo *root, ResultCachePath *rcpath,
 	 * size itself.  Really this is not the right place to do this, but it's
 	 * convenient since everything is already calculated.
 	 */
-	rcpath->est_entries = Min(Min(ndistinct, est_cache_entries),
-							  PG_UINT32_MAX);
+	mpath->est_entries = Min(Min(ndistinct, est_cache_entries),
+							 PG_UINT32_MAX);
 
 	/*
 	 * When the number of distinct parameter values is above the amount we can
@@ -4285,10 +4285,10 @@ cost_rescan(PlannerInfo *root, Path *path,
 				*rescan_total_cost = run_cost;
 			}
 			break;
-		case T_ResultCache:
-			/* All the hard work is done by cost_resultcache_rescan */
-			cost_resultcache_rescan(root, (ResultCachePath *) path,
-									rescan_startup_cost, rescan_total_cost);
+		case T_Memoize:
+			/* All the hard work is done by cost_memoize_rescan */
+			cost_memoize_rescan(root, (MemoizePath *) path,
+								rescan_startup_cost, rescan_total_cost);
 			break;
 		default:
 			*rescan_startup_cost = path->startup_cost;

src/backend/optimizer/path/joinpath.c

@@ -171,7 +171,7 @@ add_paths_to_joinrel(PlannerInfo *root,
 		case JOIN_ANTI:
 
 			/*
-			 * XXX it may be worth proving this to allow a ResultCache to be
+			 * XXX it may be worth proving this to allow a Memoize to be
 			 * considered for Nested Loop Semi/Anti Joins.
 			 */
 			extra.inner_unique = false; /* well, unproven */
@@ -395,7 +395,7 @@ paraminfo_get_equal_hashops(PlannerInfo *root, ParamPathInfo *param_info,
 			OpExpr	   *opexpr;
 			Node	   *expr;
 
-			/* can't use result cache without a valid hash equals operator */
+			/* can't use a memoize node without a valid hash equals operator */
 			if (!OidIsValid(rinfo->hasheqoperator) ||
 				!clause_sides_match_join(rinfo, outerrel, innerrel))
 			{
@@ -436,7 +436,7 @@ paraminfo_get_equal_hashops(PlannerInfo *root, ParamPathInfo *param_info,
 		typentry = lookup_type_cache(exprType(expr),
 									 TYPECACHE_HASH_PROC | TYPECACHE_EQ_OPR);
 
-		/* can't use result cache without a valid hash equals operator */
+		/* can't use a memoize node without a valid hash equals operator */
 		if (!OidIsValid(typentry->hash_proc) || !OidIsValid(typentry->eq_opr))
 		{
 			list_free(*operators);
@@ -448,27 +448,27 @@ paraminfo_get_equal_hashops(PlannerInfo *root, ParamPathInfo *param_info,
 		*param_exprs = lappend(*param_exprs, expr);
 	}
 
-	/* We're okay to use result cache */
+	/* We're okay to use memoize */
 	return true;
 }
 
 /*
- * get_resultcache_path
- *		If possible, make and return a Result Cache path atop of 'inner_path'.
+ * get_memoize_path
+ *		If possible, make and return a Memoize path atop of 'inner_path'.
  *		Otherwise return NULL.
  */
 static Path *
-get_resultcache_path(PlannerInfo *root, RelOptInfo *innerrel,
-					 RelOptInfo *outerrel, Path *inner_path,
-					 Path *outer_path, JoinType jointype,
-					 JoinPathExtraData *extra)
+get_memoize_path(PlannerInfo *root, RelOptInfo *innerrel,
+				 RelOptInfo *outerrel, Path *inner_path,
+				 Path *outer_path, JoinType jointype,
+				 JoinPathExtraData *extra)
 {
 	List	   *param_exprs;
 	List	   *hash_operators;
 	ListCell   *lc;
 
 	/* Obviously not if it's disabled */
-	if (!enable_resultcache)
+	if (!enable_memoize)
 		return NULL;
 
 	/*
@@ -481,7 +481,7 @@ get_resultcache_path(PlannerInfo *root, RelOptInfo *innerrel,
 		return NULL;
 
 	/*
-	 * We can only have a result cache when there's some kind of cache key,
+	 * We can only have a memoize node when there's some kind of cache key,
 	 * either parameterized path clauses or lateral Vars.  No cache key sounds
 	 * more like something a Materialize node might be more useful for.
 	 */
@@ -493,8 +493,8 @@ get_resultcache_path(PlannerInfo *root, RelOptInfo *innerrel,
 	/*
 	 * Currently we don't do this for SEMI and ANTI joins unless they're
 	 * marked as inner_unique.  This is because nested loop SEMI/ANTI joins
-	 * don't scan the inner node to completion, which will mean result cache
-	 * cannot mark the cache entry as complete.
+	 * don't scan the inner node to completion, which will mean memoize cannot
+	 * mark the cache entry as complete.
 	 *
 	 * XXX Currently we don't attempt to mark SEMI/ANTI joins as inner_unique
 	 * = true.  Should we?  See add_paths_to_joinrel()
@@ -504,8 +504,8 @@ get_resultcache_path(PlannerInfo *root, RelOptInfo *innerrel,
 		return NULL;
 
 	/*
-	 * Result Cache normally marks cache entries as complete when it runs out
-	 * of tuples to read from its subplan.  However, with unique joins, Nested
+	 * Memoize normally marks cache entries as complete when it runs out of
+	 * tuples to read from its subplan.  However, with unique joins, Nested
 	 * Loop will skip to the next outer tuple after finding the first matching
 	 * inner tuple.  This means that we may not read the inner side of the
 	 * join to completion which leaves no opportunity to mark the cache entry
@@ -516,11 +516,11 @@ get_resultcache_path(PlannerInfo *root, RelOptInfo *innerrel,
 	 * condition, we can't be sure which part of it causes the join to be
 	 * unique.  This means there are no guarantees that only 1 tuple will be
 	 * read.  We cannot mark the cache entry as complete after reading the
-	 * first tuple without that guarantee.  This means the scope of Result
-	 * Cache's usefulness is limited to only outer rows that have no join
+	 * first tuple without that guarantee.  This means the scope of Memoize
+	 * node's usefulness is limited to only outer rows that have no join
 	 * partner as this is the only case where Nested Loop would exhaust the
 	 * inner scan of a unique join.  Since the scope is limited to that, we
-	 * just don't bother making a result cache path in this case.
+	 * just don't bother making a memoize path in this case.
 	 *
 	 * Lateral vars needn't be considered here as they're not considered when
 	 * determining if the join is unique.
@@ -536,7 +536,7 @@ get_resultcache_path(PlannerInfo *root, RelOptInfo *innerrel,
 		return NULL;
 
 	/*
-	 * We can't use a result cache if there are volatile functions in the
+	 * We can't use a memoize node if there are volatile functions in the
 	 * inner rel's target list or restrict list.  A cache hit could reduce the
 	 * number of calls to these functions.
 	 */
@@ -559,13 +559,13 @@ get_resultcache_path(PlannerInfo *root, RelOptInfo *innerrel,
 									&param_exprs,
 									&hash_operators))
 	{
-		return (Path *) create_resultcache_path(root,
-												innerrel,
-												inner_path,
-												param_exprs,
-												hash_operators,
-												extra->inner_unique,
-												outer_path->parent->rows);
+		return (Path *) create_memoize_path(root,
+											innerrel,
+											inner_path,
+											param_exprs,
+											hash_operators,
+											extra->inner_unique,
+											outer_path->parent->rows);
 	}
 
 	return NULL;
@@ -1688,7 +1688,7 @@ match_unsorted_outer(PlannerInfo *root,
 			foreach(lc2, innerrel->cheapest_parameterized_paths)
 			{
 				Path	   *innerpath = (Path *) lfirst(lc2);
-				Path	   *rcpath;
+				Path	   *mpath;
 
 				try_nestloop_path(root,
 								  joinrel,
@@ -1699,17 +1699,17 @@ match_unsorted_outer(PlannerInfo *root,
 								  extra);
 
 				/*
-				 * Try generating a result cache path and see if that makes
-				 * the nested loop any cheaper.
+				 * Try generating a memoize path and see if that makes the
+				 * nested loop any cheaper.
 				 */
-				rcpath = get_resultcache_path(root, innerrel, outerrel,
-											  innerpath, outerpath, jointype,
-											  extra);
-				if (rcpath != NULL)
+				mpath = get_memoize_path(root, innerrel, outerrel,
+										 innerpath, outerpath, jointype,
+										 extra);
+				if (mpath != NULL)
 					try_nestloop_path(root,
 									  joinrel,
 									  outerpath,
-									  rcpath,
+									  mpath,
 									  merge_pathkeys,
 									  jointype,
 									  extra);
@@ -1867,7 +1867,7 @@ consider_parallel_nestloop(PlannerInfo *root,
 		foreach(lc2, innerrel->cheapest_parameterized_paths)
 		{
 			Path	   *innerpath = (Path *) lfirst(lc2);
-			Path	   *rcpath;
+			Path	   *mpath;
 
 			/* Can't join to an inner path that is not parallel-safe */
 			if (!innerpath->parallel_safe)
@@ -1894,14 +1894,14 @@ consider_parallel_nestloop(PlannerInfo *root,
 									  pathkeys, jointype, extra);
 
 			/*
-			 * Try generating a result cache path and see if that makes the
-			 * nested loop any cheaper.
+			 * Try generating a memoize path and see if that makes the nested
+			 * loop any cheaper.
 			 */
-			rcpath = get_resultcache_path(root, innerrel, outerrel,
-										  innerpath, outerpath, jointype,
-										  extra);
-			if (rcpath != NULL)
-				try_partial_nestloop_path(root, joinrel, outerpath, rcpath,
+			mpath = get_memoize_path(root, innerrel, outerrel,
+									 innerpath, outerpath, jointype,
+									 extra);
+			if (mpath != NULL)
+				try_partial_nestloop_path(root, joinrel, outerpath, mpath,
 										  pathkeys, jointype, extra);
 		}
 	}

src/backend/optimizer/plan/createplan.c

@@ -92,9 +92,8 @@ static Result *create_group_result_plan(PlannerInfo *root,
 static ProjectSet *create_project_set_plan(PlannerInfo *root, ProjectSetPath *best_path);
 static Material *create_material_plan(PlannerInfo *root, MaterialPath *best_path,
 									  int flags);
-static ResultCache *create_resultcache_plan(PlannerInfo *root,
-											ResultCachePath *best_path,
-											int flags);
+static Memoize *create_memoize_plan(PlannerInfo *root, MemoizePath *best_path,
+									int flags);
 static Plan *create_unique_plan(PlannerInfo *root, UniquePath *best_path,
 								int flags);
 static Gather *create_gather_plan(PlannerInfo *root, GatherPath *best_path);
@@ -278,11 +277,9 @@ static Sort *make_sort_from_groupcols(List *groupcls,
 									  AttrNumber *grpColIdx,
 									  Plan *lefttree);
 static Material *make_material(Plan *lefttree);
-static ResultCache *make_resultcache(Plan *lefttree, Oid *hashoperators,
-									 Oid *collations,
-									 List *param_exprs,
-									 bool singlerow,
-									 uint32 est_entries);
+static Memoize *make_memoize(Plan *lefttree, Oid *hashoperators,
+							 Oid *collations, List *param_exprs,
+							 bool singlerow, uint32 est_entries);
 static WindowAgg *make_windowagg(List *tlist, Index winref,
 								 int partNumCols, AttrNumber *partColIdx, Oid *partOperators, Oid *partCollations,
 								 int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators, Oid *ordCollations,
@@ -459,10 +456,10 @@ create_plan_recurse(PlannerInfo *root, Path *best_path, int flags)
 												 (MaterialPath *) best_path,
 												 flags);
 			break;
-		case T_ResultCache:
-			plan = (Plan *) create_resultcache_plan(root,
-													(ResultCachePath *) best_path,
-													flags);
+		case T_Memoize:
+			plan = (Plan *) create_memoize_plan(root,
+												(MemoizePath *) best_path,
+												flags);
 			break;
 		case T_Unique:
 			if (IsA(best_path, UpperUniquePath))
@@ -1578,16 +1575,16 @@ create_material_plan(PlannerInfo *root, MaterialPath *best_path, int flags)
 }
 
 /*
- * create_resultcache_plan
- *	  Create a ResultCache plan for 'best_path' and (recursively) plans
- *	  for its subpaths.
+ * create_memoize_plan
+ *	  Create a Memoize plan for 'best_path' and (recursively) plans for its
+ *	  subpaths.
  *
  *	  Returns a Plan node.
  */
-static ResultCache *
-create_resultcache_plan(PlannerInfo *root, ResultCachePath *best_path, int flags)
+static Memoize *
+create_memoize_plan(PlannerInfo *root, MemoizePath *best_path, int flags)
 {
-	ResultCache *plan;
+	Memoize    *plan;
 	Plan	   *subplan;
 	Oid		   *operators;
 	Oid		   *collations;
@@ -1619,8 +1616,8 @@ create_resultcache_plan(PlannerInfo *root, ResultCachePath *best_path, int flags
 		i++;
 	}
 
-	plan = make_resultcache(subplan, operators, collations, param_exprs,
-							best_path->singlerow, best_path->est_entries);
+	plan = make_memoize(subplan, operators, collations, param_exprs,
+						best_path->singlerow, best_path->est_entries);
 
 	copy_generic_path_info(&plan->plan, (Path *) best_path);
 
@@ -6417,11 +6414,11 @@ materialize_finished_plan(Plan *subplan)
 	return matplan;
 }
 
-static ResultCache *
-make_resultcache(Plan *lefttree, Oid *hashoperators, Oid *collations,
-				 List *param_exprs, bool singlerow, uint32 est_entries)
+static Memoize *
+make_memoize(Plan *lefttree, Oid *hashoperators, Oid *collations,
+			 List *param_exprs, bool singlerow, uint32 est_entries)
 {
-	ResultCache *node = makeNode(ResultCache);
+	Memoize    *node = makeNode(Memoize);
 	Plan	   *plan = &node->plan;
 
 	plan->targetlist = lefttree->targetlist;
@@ -7035,7 +7032,7 @@ is_projection_capable_path(Path *path)
 	{
 		case T_Hash:
 		case T_Material:
-		case T_ResultCache:
+		case T_Memoize:
 		case T_Sort:
 		case T_IncrementalSort:
 		case T_Unique:
@@ -7081,7 +7078,7 @@ is_projection_capable_plan(Plan *plan)
 	{
 		case T_Hash:
 		case T_Material:
-		case T_ResultCache:
+		case T_Memoize:
 		case T_Sort:
 		case T_Unique:
 		case T_SetOp:

src/backend/optimizer/plan/initsplan.c

@@ -78,7 +78,7 @@ static bool check_equivalence_delay(PlannerInfo *root,
 static bool check_redundant_nullability_qual(PlannerInfo *root, Node *clause);
 static void check_mergejoinable(RestrictInfo *restrictinfo);
 static void check_hashjoinable(RestrictInfo *restrictinfo);
-static void check_resultcacheable(RestrictInfo *restrictinfo);
+static void check_memoizable(RestrictInfo *restrictinfo);
 
 
 /*****************************************************************************
@@ -2212,10 +2212,10 @@ distribute_restrictinfo_to_rels(PlannerInfo *root,
 
 			/*
 			 * Likewise, check if the clause is suitable to be used with a
-			 * Result Cache node to cache inner tuples during a parameterized
+			 * Memoize node to cache inner tuples during a parameterized
 			 * nested loop.
 			 */
-			check_resultcacheable(restrictinfo);
+			check_memoizable(restrictinfo);
 
 			/*
 			 * Add clause to the join lists of all the relevant relations.
@@ -2459,7 +2459,7 @@ build_implied_join_equality(PlannerInfo *root,
 	/* Set mergejoinability/hashjoinability flags */
 	check_mergejoinable(restrictinfo);
 	check_hashjoinable(restrictinfo);
-	check_resultcacheable(restrictinfo);
+	check_memoizable(restrictinfo);
 
 	return restrictinfo;
 }
@@ -2709,13 +2709,13 @@ check_hashjoinable(RestrictInfo *restrictinfo)
 }
 
 /*
- * check_resultcacheable
- *	  If the restrictinfo's clause is suitable to be used for a Result Cache
- *	  node, set the hasheqoperator to the hash equality operator that will be
- *	  needed during caching.
+ * check_memoizable
+ *	  If the restrictinfo's clause is suitable to be used for a Memoize node,
+ *	  set the hasheqoperator to the hash equality operator that will be needed
+ *	  during caching.
  */
 static void
-check_resultcacheable(RestrictInfo *restrictinfo)
+check_memoizable(RestrictInfo *restrictinfo)
 {
 	TypeCacheEntry *typentry;
 	Expr	   *clause = restrictinfo->clause;

src/backend/optimizer/plan/setrefs.c

@@ -752,19 +752,19 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
 			set_hash_references(root, plan, rtoffset);
 			break;
 
-		case T_ResultCache:
+		case T_Memoize:
 			{
-				ResultCache *rcplan = (ResultCache *) plan;
+				Memoize    *mplan = (Memoize *) plan;
 
 				/*
-				 * Result Cache does not evaluate its targetlist.  It just
-				 * uses the same targetlist from its outer subnode.
+				 * Memoize does not evaluate its targetlist.  It just uses the
+				 * same targetlist from its outer subnode.
 				 */
 				set_dummy_tlist_references(plan, rtoffset);
 
-				rcplan->param_exprs = fix_scan_list(root, rcplan->param_exprs,
-													rtoffset,
-													NUM_EXEC_TLIST(plan));
+				mplan->param_exprs = fix_scan_list(root, mplan->param_exprs,
+												   rtoffset,
+												   NUM_EXEC_TLIST(plan));
 				break;
 			}
 

src/backend/optimizer/plan/subselect.c

@@ -2745,8 +2745,8 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 			/* rescan_param does *not* get added to scan_params */
 			break;
 
-		case T_ResultCache:
-			finalize_primnode((Node *) ((ResultCache *) plan)->param_exprs,
+		case T_Memoize:
+			finalize_primnode((Node *) ((Memoize *) plan)->param_exprs,
 							  &context);
 			break;
 

src/backend/optimizer/util/pathnode.c

@@ -1577,20 +1577,19 @@ create_material_path(RelOptInfo *rel, Path *subpath)
 }
 
 /*
- * create_resultcache_path
- *	  Creates a path corresponding to a ResultCache plan, returning the
- *	  pathnode.
+ * create_memoize_path
+ *	  Creates a path corresponding to a Memoize plan, returning the pathnode.
  */
-ResultCachePath *
-create_resultcache_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
-						List *param_exprs, List *hash_operators,
-						bool singlerow, double calls)
+MemoizePath *
+create_memoize_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
+					List *param_exprs, List *hash_operators,
+					bool singlerow, double calls)
 {
-	ResultCachePath *pathnode = makeNode(ResultCachePath);
+	MemoizePath *pathnode = makeNode(MemoizePath);
 
 	Assert(subpath->parent == rel);
 
-	pathnode->path.pathtype = T_ResultCache;
+	pathnode->path.pathtype = T_Memoize;
 	pathnode->path.parent = rel;
 	pathnode->path.pathtarget = rel->reltarget;
 	pathnode->path.param_info = subpath->param_info;
@@ -1607,17 +1606,16 @@ create_resultcache_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
 	pathnode->calls = calls;
 
 	/*
-	 * For now we set est_entries to 0.  cost_resultcache_rescan() does all
-	 * the hard work to determine how many cache entries there are likely to
-	 * be, so it seems best to leave it up to that function to fill this field
-	 * in.  If left at 0, the executor will make a guess at a good value.
+	 * For now we set est_entries to 0.  cost_memoize_rescan() does all the
+	 * hard work to determine how many cache entries there are likely to be,
+	 * so it seems best to leave it up to that function to fill this field in.
+	 * If left at 0, the executor will make a guess at a good value.
 	 */
 	pathnode->est_entries = 0;
 
 	/*
 	 * Add a small additional charge for caching the first entry.  All the
-	 * harder calculations for rescans are performed in
-	 * cost_resultcache_rescan().
+	 * harder calculations for rescans are performed in cost_memoize_rescan().
 	 */
 	pathnode->path.startup_cost = subpath->startup_cost + cpu_tuple_cost;
 	pathnode->path.total_cost = subpath->total_cost + cpu_tuple_cost;
@@ -3936,16 +3934,16 @@ reparameterize_path(PlannerInfo *root, Path *path,
 									   apath->path.parallel_aware,
 									   -1);
 			}
-		case T_ResultCache:
+		case T_Memoize:
 			{
-				ResultCachePath *rcpath = (ResultCachePath *) path;
-
-				return (Path *) create_resultcache_path(root, rel,
-														rcpath->subpath,
-														rcpath->param_exprs,
-														rcpath->hash_operators,
-														rcpath->singlerow,
-														rcpath->calls);
+				MemoizePath *mpath = (MemoizePath *) path;
+
+				return (Path *) create_memoize_path(root, rel,
+													mpath->subpath,
+													mpath->param_exprs,
+													mpath->hash_operators,
+													mpath->singlerow,
+													mpath->calls);
 			}
 		default:
 			break;
@@ -4165,13 +4163,13 @@ do { \
 			}
 			break;
 
-		case T_ResultCachePath:
+		case T_MemoizePath:
 			{
-				ResultCachePath *rcpath;
+				MemoizePath *mpath;
 
-				FLAT_COPY_PATH(rcpath, path, ResultCachePath);
-				REPARAMETERIZE_CHILD_PATH(rcpath->subpath);
-				new_path = (Path *) rcpath;
+				FLAT_COPY_PATH(mpath, path, MemoizePath);
+				REPARAMETERIZE_CHILD_PATH(mpath->subpath);
+				new_path = (Path *) mpath;
 			}
 			break;
 

src/backend/utils/misc/guc.c

@@ -1042,12 +1042,12 @@ static struct config_bool ConfigureNamesBool[] =
 		NULL, NULL, NULL
 	},
 	{
-		{"enable_resultcache", PGC_USERSET, QUERY_TUNING_METHOD,
-			gettext_noop("Enables the planner's use of result caching."),
+		{"enable_memoize", PGC_USERSET, QUERY_TUNING_METHOD,
+			gettext_noop("Enables the planner's use of memoization."),
 			NULL,
 			GUC_EXPLAIN
 		},
-		&enable_resultcache,
+		&enable_memoize,
 		true,
 		NULL, NULL, NULL
 	},

src/backend/utils/misc/postgresql.conf.sample

@@ -366,7 +366,7 @@
 #enable_indexscan = on
 #enable_indexonlyscan = on
 #enable_material = on
-#enable_resultcache = on
+#enable_memoize = on
 #enable_mergejoin = on
 #enable_nestloop = on
 #enable_parallel_append = on

src/include/executor/nodeResultCache.h → src/include/executor/nodeMemoize.h

 /*-------------------------------------------------------------------------
  *
- * nodeResultCache.h
+ * nodeMemoize.h
  *
  *
  *
  * Portions Copyright (c) 2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * src/include/executor/nodeResultCache.h
+ * src/include/executor/nodeMemoize.h
  *
  *-------------------------------------------------------------------------
  */
-#ifndef NODERESULTCACHE_H
-#define NODERESULTCACHE_H
+#ifndef NODEMEMOIZE_H
+#define NODEMEMOIZE_H
 
 #include "access/parallel.h"
 #include "nodes/execnodes.h"
 
-extern ResultCacheState *ExecInitResultCache(ResultCache *node, EState *estate, int eflags);
-extern void ExecEndResultCache(ResultCacheState *node);
-extern void ExecReScanResultCache(ResultCacheState *node);
+extern MemoizeState *ExecInitMemoize(Memoize *node, EState *estate, int eflags);
+extern void ExecEndMemoize(MemoizeState *node);
+extern void ExecReScanMemoize(MemoizeState *node);
 extern double ExecEstimateCacheEntryOverheadBytes(double ntuples);
-extern void ExecResultCacheEstimate(ResultCacheState *node,
-									ParallelContext *pcxt);
-extern void ExecResultCacheInitializeDSM(ResultCacheState *node,
-										 ParallelContext *pcxt);
-extern void ExecResultCacheInitializeWorker(ResultCacheState *node,
-											ParallelWorkerContext *pwcxt);
-extern void ExecResultCacheRetrieveInstrumentation(ResultCacheState *node);
+extern void ExecMemoizeEstimate(MemoizeState *node,
+								ParallelContext *pcxt);
+extern void ExecMemoizeInitializeDSM(MemoizeState *node,
+									 ParallelContext *pcxt);
+extern void ExecMemoizeInitializeWorker(MemoizeState *node,
+										ParallelWorkerContext *pwcxt);
+extern void ExecMemoizeRetrieveInstrumentation(MemoizeState *node);
 
-#endif							/* NODERESULTCACHE_H */
+#endif							/* NODEMEMOIZE_H */

src/include/nodes/execnodes.h

@@ -2046,11 +2046,11 @@ typedef struct MaterialState
 	Tuplestorestate *tuplestorestate;
 } MaterialState;
 
-struct ResultCacheEntry;
-struct ResultCacheTuple;
-struct ResultCacheKey;
+struct MemoizeEntry;
+struct MemoizeTuple;
+struct MemoizeKey;
 
-typedef struct ResultCacheInstrumentation
+typedef struct MemoizeInstrumentation
 {
 	uint64		cache_hits;		/* number of rescans where we've found the
 								 * scan parameter values to be cached */
@@ -2063,31 +2063,31 @@ typedef struct ResultCacheInstrumentation
 									 * able to free enough space to store the
 									 * current scan's tuples. */
 	uint64		mem_peak;		/* peak memory usage in bytes */
-} ResultCacheInstrumentation;
+} MemoizeInstrumentation;
 
 /* ----------------
- *	 Shared memory container for per-worker resultcache information
+ *	 Shared memory container for per-worker memoize information
  * ----------------
  */
-typedef struct SharedResultCacheInfo
+typedef struct SharedMemoizeInfo
 {
 	int			num_workers;
-	ResultCacheInstrumentation sinstrument[FLEXIBLE_ARRAY_MEMBER];
-} SharedResultCacheInfo;
+	MemoizeInstrumentation sinstrument[FLEXIBLE_ARRAY_MEMBER];
+} SharedMemoizeInfo;
 
 /* ----------------
- *	 ResultCacheState information
+ *	 MemoizeState information
  *
- *		resultcache nodes are used to cache recent and commonly seen results
- *		from a parameterized scan.
+ *		memoize nodes are used to cache recent and commonly seen results from
+ *		a parameterized scan.
  * ----------------
  */
-typedef struct ResultCacheState
+typedef struct MemoizeState
 {
 	ScanState	ss;				/* its first field is NodeTag */
-	int			rc_status;		/* value of ExecResultCache state machine */
+	int			mstatus;		/* value of ExecMemoize state machine */
 	int			nkeys;			/* number of cache keys */
-	struct resultcache_hash *hashtable; /* hash table for cache entries */
+	struct memoize_hash *hashtable; /* hash table for cache entries */
 	TupleDesc	hashkeydesc;	/* tuple descriptor for cache keys */
 	TupleTableSlot *tableslot;	/* min tuple slot for existing cache entries */
 	TupleTableSlot *probeslot;	/* virtual slot used for hash lookups */
@@ -2100,17 +2100,17 @@ typedef struct ResultCacheState
 	uint64		mem_limit;		/* memory limit in bytes for the cache */
 	MemoryContext tableContext; /* memory context to store cache data */
 	dlist_head	lru_list;		/* least recently used entry list */
-	struct ResultCacheTuple *last_tuple;	/* Used to point to the last tuple
-											 * returned during a cache hit and
-											 * the tuple we last stored when
-											 * populating the cache. */
-	struct ResultCacheEntry *entry; /* the entry that 'last_tuple' belongs to
-									 * or NULL if 'last_tuple' is NULL. */
+	struct MemoizeTuple *last_tuple;	/* Used to point to the last tuple
+										 * returned during a cache hit and the
+										 * tuple we last stored when
+										 * populating the cache. */
+	struct MemoizeEntry *entry; /* the entry that 'last_tuple' belongs to or
+								 * NULL if 'last_tuple' is NULL. */
 	bool		singlerow;		/* true if the cache entry is to be marked as
 								 * complete after caching the first tuple. */
-	ResultCacheInstrumentation stats;	/* execution statistics */
-	SharedResultCacheInfo *shared_info; /* statistics for parallel workers */
-} ResultCacheState;
+	MemoizeInstrumentation stats;	/* execution statistics */
+	SharedMemoizeInfo *shared_info; /* statistics for parallel workers */
+} MemoizeState;
 
 /* ----------------
  *	 When performing sorting by multiple keys, it's possible that the input

src/include/nodes/nodes.h

@@ -74,7 +74,7 @@ typedef enum NodeTag
 	T_MergeJoin,
 	T_HashJoin,
 	T_Material,
-	T_ResultCache,
+	T_Memoize,
 	T_Sort,
 	T_IncrementalSort,
 	T_Group,
@@ -133,7 +133,7 @@ typedef enum NodeTag
 	T_MergeJoinState,
 	T_HashJoinState,
 	T_MaterialState,
-	T_ResultCacheState,
+	T_MemoizeState,
 	T_SortState,
 	T_IncrementalSortState,
 	T_GroupState,
@@ -244,7 +244,7 @@ typedef enum NodeTag
 	T_MergeAppendPath,
 	T_GroupResultPath,
 	T_MaterialPath,
-	T_ResultCachePath,
+	T_MemoizePath,
 	T_UniquePath,
 	T_GatherPath,
 	T_GatherMergePath,

src/include/nodes/pathnodes.h

@@ -1495,11 +1495,11 @@ typedef struct MaterialPath
 } MaterialPath;
 
 /*
- * ResultCachePath represents a ResultCache plan node, i.e., a cache that
- * caches tuples from parameterized paths to save the underlying node from
- * having to be rescanned for parameter values which are already cached.
+ * MemoizePath represents a Memoize plan node, i.e., a cache that caches
+ * tuples from parameterized paths to save the underlying node from having to
+ * be rescanned for parameter values which are already cached.
  */
-typedef struct ResultCachePath
+typedef struct MemoizePath
 {
 	Path		path;
 	Path	   *subpath;		/* outerpath to cache tuples from */
@@ -1511,7 +1511,7 @@ typedef struct ResultCachePath
 	uint32		est_entries;	/* The maximum number of entries that the
 								 * planner expects will fit in the cache, or 0
 								 * if unknown */
-} ResultCachePath;
+} MemoizePath;
 
 /*
  * UniquePath represents elimination of distinct rows from the output of
@@ -2111,7 +2111,7 @@ typedef struct RestrictInfo
 	Selectivity left_mcvfreq;	/* left side's most common val's freq */
 	Selectivity right_mcvfreq;	/* right side's most common val's freq */
 
-	/* hash equality operator used for result cache, else InvalidOid */
+	/* hash equality operator used for memoize nodes, else InvalidOid */
 	Oid			hasheqoperator;
 } RestrictInfo;
 

src/include/nodes/plannodes.h

@@ -781,10 +781,10 @@ typedef struct Material
 } Material;
 
 /* ----------------
- *		result cache node
+ *		memoize node
  * ----------------
  */
-typedef struct ResultCache
+typedef struct Memoize
 {
 	Plan		plan;
 
@@ -799,7 +799,7 @@ typedef struct ResultCache
 	uint32		est_entries;	/* The maximum number of entries that the
 								 * planner expects will fit in the cache, or 0
 								 * if unknown */
-} ResultCache;
+} Memoize;
 
 /* ----------------
  *		sort node

src/include/optimizer/cost.h

@@ -57,7 +57,7 @@ extern PGDLLIMPORT bool enable_incremental_sort;
 extern PGDLLIMPORT bool enable_hashagg;
 extern PGDLLIMPORT bool enable_nestloop;
 extern PGDLLIMPORT bool enable_material;
-extern PGDLLIMPORT bool enable_resultcache;
+extern PGDLLIMPORT bool enable_memoize;
 extern PGDLLIMPORT bool enable_mergejoin;
 extern PGDLLIMPORT bool enable_hashjoin;
 extern PGDLLIMPORT bool enable_gathermerge;

src/include/optimizer/pathnode.h

@@ -82,13 +82,13 @@ extern GroupResultPath *create_group_result_path(PlannerInfo *root,
 												 PathTarget *target,
 												 List *havingqual);
 extern MaterialPath *create_material_path(RelOptInfo *rel, Path *subpath);
-extern ResultCachePath *create_resultcache_path(PlannerInfo *root,
-												RelOptInfo *rel,
-												Path *subpath,
-												List *param_exprs,
-												List *hash_operators,
-												bool singlerow,
-												double calls);
+extern MemoizePath *create_memoize_path(PlannerInfo *root,
+										RelOptInfo *rel,
+										Path *subpath,
+										List *param_exprs,
+										List *hash_operators,
+										bool singlerow,
+										double calls);
 extern UniquePath *create_unique_path(PlannerInfo *root, RelOptInfo *rel,
 									  Path *subpath, SpecialJoinInfo *sjinfo);
 extern GatherPath *create_gather_path(PlannerInfo *root,

src/test/regress/expected/aggregates.out

@@ -2584,7 +2584,7 @@ select v||'a', case when v||'a' = 'aa' then 1 else 0 end, count(*)
 -- Make sure that generation of HashAggregate for uniqification purposes
 -- does not lead to array overflow due to unexpected duplicate hash keys
 -- see CAFeeJoKKu0u+A_A9R9316djW-YW3-+Gtgvy3ju655qRHR3jtdA@mail.gmail.com
-set enable_resultcache to off;
+set enable_memoize to off;
 explain (costs off)
   select 1 from tenk1
    where (hundred, thousand) in (select twothousand, twothousand from onek);
@@ -2600,7 +2600,7 @@ explain (costs off)
                ->  Seq Scan on onek
 (8 rows)
 
-reset enable_resultcache;
+reset enable_memoize;
 --
 -- Hash Aggregation Spill tests
 --

src/test/regress/expected/join.out

@@ -2536,7 +2536,7 @@ reset enable_nestloop;
 --
 set work_mem to '64kB';
 set enable_mergejoin to off;
-set enable_resultcache to off;
+set enable_memoize to off;
 explain (costs off)
 select count(*) from tenk1 a, tenk1 b
   where a.hundred = b.thousand and (b.fivethous % 10) < 10;
@@ -2560,7 +2560,7 @@ select count(*) from tenk1 a, tenk1 b
 
 reset work_mem;
 reset enable_mergejoin;
-reset enable_resultcache;
+reset enable_memoize;
 --
 -- regression test for 8.2 bug with improper re-ordering of left joins
 --
@@ -3684,7 +3684,7 @@ where t1.unique1 = 1;
                Recheck Cond: (t1.hundred = hundred)
                ->  Bitmap Index Scan on tenk1_hundred
                      Index Cond: (hundred = t1.hundred)
-         ->  Result Cache
+         ->  Memoize
                Cache Key: t2.thousand
                ->  Index Scan using tenk1_unique2 on tenk1 t3
                      Index Cond: (unique2 = t2.thousand)
@@ -3706,7 +3706,7 @@ where t1.unique1 = 1;
                Recheck Cond: (t1.hundred = hundred)
                ->  Bitmap Index Scan on tenk1_hundred
                      Index Cond: (hundred = t1.hundred)
-         ->  Result Cache
+         ->  Memoize
                Cache Key: t2.thousand
                ->  Index Scan using tenk1_unique2 on tenk1 t3
                      Index Cond: (unique2 = t2.thousand)
@@ -4235,7 +4235,7 @@ where t1.f1 = ss.f1;
                ->  Seq Scan on public.int8_tbl i8
                      Output: i8.q1, i8.q2
                      Filter: (i8.q2 = 123)
-   ->  Result Cache
+   ->  Memoize
          Output: (i8.q1), t2.f1
          Cache Key: i8.q1
          ->  Limit
@@ -4279,14 +4279,14 @@ where t1.f1 = ss2.f1;
                      ->  Seq Scan on public.int8_tbl i8
                            Output: i8.q1, i8.q2
                            Filter: (i8.q2 = 123)
-         ->  Result Cache
+         ->  Memoize
                Output: (i8.q1), t2.f1
                Cache Key: i8.q1
                ->  Limit
                      Output: (i8.q1), t2.f1
                      ->  Seq Scan on public.text_tbl t2
                            Output: i8.q1, t2.f1
-   ->  Result Cache
+   ->  Memoize
          Output: ((i8.q1)), (t2.f1)
          Cache Key: (i8.q1), t2.f1
          ->  Limit
@@ -4339,7 +4339,7 @@ where tt1.f1 = ss1.c0;
                      ->  Seq Scan on public.text_tbl tt4
                            Output: tt4.f1
                            Filter: (tt4.f1 = 'foo'::text)
-   ->  Result Cache
+   ->  Memoize
          Output: ss1.c0
          Cache Key: tt4.f1
          ->  Subquery Scan on ss1
@@ -5028,7 +5028,7 @@ explain (costs off)
  Aggregate
    ->  Nested Loop
          ->  Seq Scan on tenk1 a
-         ->  Result Cache
+         ->  Memoize
                Cache Key: a.two
                ->  Function Scan on generate_series g
 (6 rows)
@@ -5040,7 +5040,7 @@ explain (costs off)
  Aggregate
    ->  Nested Loop
          ->  Seq Scan on tenk1 a
-         ->  Result Cache
+         ->  Memoize
                Cache Key: a.two
                ->  Function Scan on generate_series g
 (6 rows)
@@ -5053,7 +5053,7 @@ explain (costs off)
  Aggregate
    ->  Nested Loop
          ->  Seq Scan on tenk1 a
-         ->  Result Cache
+         ->  Memoize
                Cache Key: a.two
                ->  Function Scan on generate_series g
 (6 rows)
@@ -5115,7 +5115,7 @@ explain (costs off)
          ->  Nested Loop
                ->  Index Only Scan using tenk1_unique1 on tenk1 a
                ->  Values Scan on "*VALUES*"
-         ->  Result Cache
+         ->  Memoize
                Cache Key: "*VALUES*".column1
                ->  Index Only Scan using tenk1_unique2 on tenk1 b
                      Index Cond: (unique2 = "*VALUES*".column1)

src/test/regress/expected/resultcache.out → src/test/regress/expected/memoize.out

--- Perform tests on the Result Cache node.
--- The cache hits/misses/evictions from the Result Cache node can vary between
+-- Perform tests on the Memoize node.
+-- The cache hits/misses/evictions from the Memoize node can vary between
 -- machines.  Let's just replace the number with an 'N'.  In order to allow us
 -- to perform validation when the measure was zero, we replace a zero value
 -- with "Zero".  All other numbers are replaced with 'N'.
-create function explain_resultcache(query text, hide_hitmiss bool) returns setof text
+create function explain_memoize(query text, hide_hitmiss bool) returns setof text
 language plpgsql as
 $$
 declare
@@ -28,21 +28,21 @@ begin
     end loop;
 end;
 $$;
--- Ensure we get a result cache on the inner side of the nested loop
+-- Ensure we get a memoize node on the inner side of the nested loop
 SET enable_hashjoin TO off;
 SET enable_bitmapscan TO off;
-SELECT explain_resultcache('
+SELECT explain_memoize('
 SELECT COUNT(*),AVG(t1.unique1) FROM tenk1 t1
 INNER JOIN tenk1 t2 ON t1.unique1 = t2.twenty
 WHERE t2.unique1 < 1000;', false);
-                                    explain_resultcache                                    
+                                      explain_memoize                                      
 -------------------------------------------------------------------------------------------
  Aggregate (actual rows=1 loops=N)
    ->  Nested Loop (actual rows=1000 loops=N)
          ->  Seq Scan on tenk1 t2 (actual rows=1000 loops=N)
                Filter: (unique1 < 1000)
                Rows Removed by Filter: 9000
-         ->  Result Cache (actual rows=1 loops=N)
+         ->  Memoize (actual rows=1 loops=N)
                Cache Key: t2.twenty
                Hits: 980  Misses: 20  Evictions: Zero  Overflows: 0  Memory Usage: NkB
                ->  Index Only Scan using tenk1_unique1 on tenk1 t1 (actual rows=1 loops=N)
@@ -60,18 +60,18 @@ WHERE t2.unique1 < 1000;
 (1 row)
 
 -- Try with LATERAL joins
-SELECT explain_resultcache('
+SELECT explain_memoize('
 SELECT COUNT(*),AVG(t2.unique1) FROM tenk1 t1,
 LATERAL (SELECT t2.unique1 FROM tenk1 t2 WHERE t1.twenty = t2.unique1) t2
 WHERE t1.unique1 < 1000;', false);
-                                    explain_resultcache                                    
+                                      explain_memoize                                      
 -------------------------------------------------------------------------------------------
  Aggregate (actual rows=1 loops=N)
    ->  Nested Loop (actual rows=1000 loops=N)
          ->  Seq Scan on tenk1 t1 (actual rows=1000 loops=N)
                Filter: (unique1 < 1000)
                Rows Removed by Filter: 9000
-         ->  Result Cache (actual rows=1 loops=N)
+         ->  Memoize (actual rows=1 loops=N)
                Cache Key: t1.twenty
                Hits: 980  Misses: 20  Evictions: Zero  Overflows: 0  Memory Usage: NkB
                ->  Index Only Scan using tenk1_unique1 on tenk1 t2 (actual rows=1 loops=N)
@@ -94,18 +94,18 @@ SET enable_mergejoin TO off;
 -- Ensure we get some evictions.  We're unable to validate the hits and misses
 -- here as the number of entries that fit in the cache at once will vary
 -- between different machines.
-SELECT explain_resultcache('
+SELECT explain_memoize('
 SELECT COUNT(*),AVG(t1.unique1) FROM tenk1 t1
 INNER JOIN tenk1 t2 ON t1.unique1 = t2.thousand
 WHERE t2.unique1 < 1200;', true);
-                                    explain_resultcache                                    
+                                      explain_memoize                                      
 -------------------------------------------------------------------------------------------
  Aggregate (actual rows=1 loops=N)
    ->  Nested Loop (actual rows=1200 loops=N)
          ->  Seq Scan on tenk1 t2 (actual rows=1200 loops=N)
                Filter: (unique1 < 1200)
                Rows Removed by Filter: 8800
-         ->  Result Cache (actual rows=1 loops=N)
+         ->  Memoize (actual rows=1 loops=N)
                Cache Key: t2.thousand
                Hits: N  Misses: N  Evictions: N  Overflows: 0  Memory Usage: NkB
                ->  Index Only Scan using tenk1_unique1 on tenk1 t1 (actual rows=1 loops=N)
@@ -117,7 +117,7 @@ RESET enable_mergejoin;
 RESET work_mem;
 RESET enable_bitmapscan;
 RESET enable_hashjoin;
--- Test parallel plans with Result Cache.
+-- Test parallel plans with Memoize
 SET min_parallel_table_scan_size TO 0;
 SET parallel_setup_cost TO 0;
 SET parallel_tuple_cost TO 0;
@@ -138,7 +138,7 @@ WHERE t1.unique1 < 1000;
                            Recheck Cond: (unique1 < 1000)
                            ->  Bitmap Index Scan on tenk1_unique1
                                  Index Cond: (unique1 < 1000)
-                     ->  Result Cache
+                     ->  Memoize
                            Cache Key: t1.twenty
                            ->  Index Only Scan using tenk1_unique1 on tenk1 t2
                                  Index Cond: (unique1 = t1.twenty)

src/test/regress/expected/partition_prune.out

@@ -2085,7 +2085,7 @@ create index ab_a3_b2_a_idx on ab_a3_b2 (a);
 create index ab_a3_b3_a_idx on ab_a3_b3 (a);
 set enable_hashjoin = 0;
 set enable_mergejoin = 0;
-set enable_resultcache = 0;
+set enable_memoize = 0;
 select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on ab.a = a.a where a.a in(0, 0, 1)');
                                         explain_parallel_append                                         
 --------------------------------------------------------------------------------------------------------
@@ -2254,7 +2254,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
 
 reset enable_hashjoin;
 reset enable_mergejoin;
-reset enable_resultcache;
+reset enable_memoize;
 reset parallel_setup_cost;
 reset parallel_tuple_cost;
 reset min_parallel_table_scan_size;

src/test/regress/expected/subselect.out

@@ -1097,7 +1097,7 @@ where o.ten = 1;
    ->  Nested Loop
          ->  Seq Scan on onek o
                Filter: (ten = 1)
-         ->  Result Cache
+         ->  Memoize
                Cache Key: o.four
                ->  CTE Scan on x
                      CTE x

src/test/regress/expected/sysviews.out

@@ -104,6 +104,7 @@ select name, setting from pg_settings where name like 'enable%';
  enable_indexonlyscan           | on
  enable_indexscan               | on
  enable_material                | on
+ enable_memoize                 | on
  enable_mergejoin               | on
  enable_nestloop                | on
  enable_parallel_append         | on
@@ -111,7 +112,6 @@ select name, setting from pg_settings where name like 'enable%';
  enable_partition_pruning       | on
  enable_partitionwise_aggregate | off
  enable_partitionwise_join      | off
- enable_resultcache             | on
  enable_seqscan                 | on
  enable_sort                    | on
  enable_tidscan                 | on

src/test/regress/parallel_schedule

@@ -120,7 +120,7 @@ test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion tr
 # ----------
 # Another group of parallel tests
 # ----------
-test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression resultcache
+test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression memoize
 
 # event triggers cannot run concurrently with any test that runs DDL
 # oidjoins is read-only, though, and should run late for best coverage

src/test/regress/sql/aggregates.sql

@@ -1098,11 +1098,11 @@ select v||'a', case when v||'a' = 'aa' then 1 else 0 end, count(*)
 -- Make sure that generation of HashAggregate for uniqification purposes
 -- does not lead to array overflow due to unexpected duplicate hash keys
 -- see CAFeeJoKKu0u+A_A9R9316djW-YW3-+Gtgvy3ju655qRHR3jtdA@mail.gmail.com
-set enable_resultcache to off;
+set enable_memoize to off;
 explain (costs off)
   select 1 from tenk1
    where (hundred, thousand) in (select twothousand, twothousand from onek);
-reset enable_resultcache;
+reset enable_memoize;
 
 --
 -- Hash Aggregation Spill tests

src/test/regress/sql/join.sql

@@ -550,7 +550,7 @@ reset enable_nestloop;
 
 set work_mem to '64kB';
 set enable_mergejoin to off;
-set enable_resultcache to off;
+set enable_memoize to off;
 
 explain (costs off)
 select count(*) from tenk1 a, tenk1 b
@@ -560,7 +560,7 @@ select count(*) from tenk1 a, tenk1 b
 
 reset work_mem;
 reset enable_mergejoin;
-reset enable_resultcache;
+reset enable_memoize;
 
 --
 -- regression test for 8.2 bug with improper re-ordering of left joins

src/test/regress/sql/resultcache.sql → src/test/regress/sql/memoize.sql

--- Perform tests on the Result Cache node.
+-- Perform tests on the Memoize node.
 
--- The cache hits/misses/evictions from the Result Cache node can vary between
+-- The cache hits/misses/evictions from the Memoize node can vary between
 -- machines.  Let's just replace the number with an 'N'.  In order to allow us
 -- to perform validation when the measure was zero, we replace a zero value
 -- with "Zero".  All other numbers are replaced with 'N'.
-create function explain_resultcache(query text, hide_hitmiss bool) returns setof text
+create function explain_memoize(query text, hide_hitmiss bool) returns setof text
 language plpgsql as
 $$
 declare
@@ -30,11 +30,11 @@ begin
 end;
 $$;
 
--- Ensure we get a result cache on the inner side of the nested loop
+-- Ensure we get a memoize node on the inner side of the nested loop
 SET enable_hashjoin TO off;
 SET enable_bitmapscan TO off;
 
-SELECT explain_resultcache('
+SELECT explain_memoize('
 SELECT COUNT(*),AVG(t1.unique1) FROM tenk1 t1
 INNER JOIN tenk1 t2 ON t1.unique1 = t2.twenty
 WHERE t2.unique1 < 1000;', false);
@@ -45,7 +45,7 @@ INNER JOIN tenk1 t2 ON t1.unique1 = t2.twenty
 WHERE t2.unique1 < 1000;
 
 -- Try with LATERAL joins
-SELECT explain_resultcache('
+SELECT explain_memoize('
 SELECT COUNT(*),AVG(t2.unique1) FROM tenk1 t1,
 LATERAL (SELECT t2.unique1 FROM tenk1 t2 WHERE t1.twenty = t2.unique1) t2
 WHERE t1.unique1 < 1000;', false);
@@ -61,7 +61,7 @@ SET enable_mergejoin TO off;
 -- Ensure we get some evictions.  We're unable to validate the hits and misses
 -- here as the number of entries that fit in the cache at once will vary
 -- between different machines.
-SELECT explain_resultcache('
+SELECT explain_memoize('
 SELECT COUNT(*),AVG(t1.unique1) FROM tenk1 t1
 INNER JOIN tenk1 t2 ON t1.unique1 = t2.thousand
 WHERE t2.unique1 < 1200;', true);
@@ -70,7 +70,7 @@ RESET work_mem;
 RESET enable_bitmapscan;
 RESET enable_hashjoin;
 
--- Test parallel plans with Result Cache.
+-- Test parallel plans with Memoize
 SET min_parallel_table_scan_size TO 0;
 SET parallel_setup_cost TO 0;
 SET parallel_tuple_cost TO 0;

src/test/regress/sql/partition_prune.sql

@@ -515,7 +515,7 @@ create index ab_a3_b3_a_idx on ab_a3_b3 (a);
 
 set enable_hashjoin = 0;
 set enable_mergejoin = 0;
-set enable_resultcache = 0;
+set enable_memoize = 0;
 
 select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on ab.a = a.a where a.a in(0, 0, 1)');
 
@@ -534,7 +534,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
 
 reset enable_hashjoin;
 reset enable_mergejoin;
-reset enable_resultcache;
+reset enable_memoize;
 reset parallel_setup_cost;
 reset parallel_tuple_cost;
 reset min_parallel_table_scan_size;

src/tools/pgindent/typedefs.list

@@ -1421,6 +1421,13 @@ Material
 MaterialPath
 MaterialState
 MdfdVec
+Memoize
+MemoizeEntry
+MemoizeInstrumentation
+MemoizeKey
+MemoizePath
+MemoizeState
+MemoizeTuple
 MemoryContext
 MemoryContextCallback
 MemoryContextCallbackFunction
@@ -2222,13 +2229,6 @@ RestoreOptions
 RestorePass
 RestrictInfo
 Result
-ResultCache
-ResultCacheEntry
-ResultCacheInstrumentation
-ResultCacheKey
-ResultCachePath
-ResultCacheState
-ResultCacheTuple
 ResultRelInfo
 ResultState
 ReturnSetInfo
@@ -2384,10 +2384,10 @@ SharedInvalSmgrMsg
 SharedInvalSnapshotMsg
 SharedInvalidationMessage
 SharedJitInstrumentation
+SharedMemoizeInfo
 SharedRecordTableEntry
 SharedRecordTableKey
 SharedRecordTypmodRegistry
-SharedResultCacheInfo
 SharedSortInfo
 SharedTuplestore
 SharedTuplestoreAccessor
@@ -3270,6 +3270,8 @@ mbcharacter_incrementer
 mbdisplaylen_converter
 mblen_converter
 mbstr_verifier
+memoize_hash
+memoize_iterator
 metastring
 mix_data_t
 mixedStruct
@@ -3474,8 +3476,6 @@ remoteDep
 rendezvousHashEntry
 replace_rte_variables_callback
 replace_rte_variables_context
-resultcache_hash
-resultcache_iterator
 ret_type
 rewind_source
 rewrite_event