memoize_display_hash_buckets.patch

diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index d2a2479822..c535d63883 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -3177,6 +3177,11 @@ show_memoize_info(MemoizeState *mstate, List *ancestors, ExplainState *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);
+			ExplainPropertyInteger("Maximum Hash Buckets", NULL,
+				mstate->stats.hashsize_max, es);
+			ExplainPropertyInteger("Original Hash Buckets", NULL,
+				mstate->stats.hashsize_orig, es);
+
 		}
 		else
 		{
@@ -3188,6 +3193,14 @@ show_memoize_info(MemoizeState *mstate, List *ancestors, ExplainState *es)
 							 mstate->stats.cache_evictions,
 							 mstate->stats.cache_overflows,
 							 memPeakKb);
+			ExplainIndentText(es);
+			if (mstate->stats.hashsize_max != mstate->stats.hashsize_orig)
+				appendStringInfo(es->str, "Hash Buckets: %u (originally %u)\n",
+								 mstate->stats.hashsize_max,
+								 mstate->stats.hashsize_orig);
+			else
+				appendStringInfo(es->str, "Hash Buckets: %u\n",
+								 mstate->stats.hashsize_max);
 		}
 	}
 
@@ -3227,6 +3240,14 @@ show_memoize_info(MemoizeState *mstate, List *ancestors, ExplainState *es)
 							 si->cache_hits, si->cache_misses,
 							 si->cache_evictions, si->cache_overflows,
 							 memPeakKb);
+			ExplainIndentText(es);
+			if (si->hashsize_max != si->hashsize_orig)
+				appendStringInfo(es->str, "Hash Buckets: %u (originally %u)\n",
+								 si->hashsize_max,
+								 si->hashsize_orig);
+			else
+				appendStringInfo(es->str, "Hash Buckets: %u\n",
+								 si->hashsize_max);
 		}
 		else
 		{
@@ -3240,6 +3261,11 @@ show_memoize_info(MemoizeState *mstate, List *ancestors, ExplainState *es)
 								   si->cache_overflows, es);
 			ExplainPropertyInteger("Peak Memory Usage", "kB", memPeakKb,
 								   es);
+			ExplainPropertyInteger("Maximum Hash Buckets", NULL,
+								   si->hashsize_max, es);
+			ExplainPropertyInteger("Original Hash Buckets", NULL,
+								   si->hashsize_orig, es);
+
 		}
 
 		if (es->workers_state)
diff --git a/src/backend/executor/nodeMemoize.c b/src/backend/executor/nodeMemoize.c
index 23441e33ca..e2a17a615f 100644
--- a/src/backend/executor/nodeMemoize.c
+++ b/src/backend/executor/nodeMemoize.c
@@ -270,6 +270,10 @@ build_hash_table(MemoizeState *mstate, uint32 size)
 
 	/* memoize_create will convert the size to a power of 2 */
 	mstate->hashtable = memoize_create(mstate->tableContext, size, mstate);
+
+	/* Record the initial size of the hash table */
+	if (mstate->stats.hashsize_orig == 0)
+		mstate->stats.hashsize_orig = mstate->hashtable->size;
 }
 
 /*
@@ -527,6 +531,10 @@ cache_lookup(MemoizeState *mstate, bool *found)
 	/* Update the total cache memory utilization */
 	mstate->mem_used += EMPTY_ENTRY_MEMORY_BYTES(entry);
 
+	/* Record the maximum size of the hash table */
+	mstate->stats.hashsize_max = Max(mstate->stats.hashsize_max,
+									 mstate->hashtable->size);
+
 	/* Initialize this entry */
 	entry->complete = false;
 	entry->tuplehead = NULL;
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 94b191f8ae..1e7012d6e8 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -2109,6 +2109,8 @@ typedef struct MemoizeInstrumentation
 									 * able to free enough space to store the
 									 * current scan's tuples. */
 	uint64		mem_peak;		/* peak memory usage in bytes */
+	uint32		hashsize_orig;	/* Original hash bucket count */
+	uint32		hashsize_max;	/* Maximum hash table bucket count */
 } MemoizeInstrumentation;
 
 /* ----------------