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

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: