1 files changed, 36 insertions, 5 deletions

diff --git a/src/backend/replication/pgoutput/pgoutput.c b/src/backend/replication/pgoutput/pgoutput.c
index df2ea94d468..9fd879ee0c8 100644
--- a/src/backend/replication/pgoutput/pgoutput.c
+++ b/src/backend/replication/pgoutput/pgoutput.c
@@ -65,6 +65,13 @@ static void pgoutput_stream_commit(struct LogicalDecodingContext *ctx,
 static bool publications_valid;
 static bool in_streaming;
 
+/*
+ * Private memory context for publication data, created in
+ * PGOutputData->context when starting pgoutput, and set to NULL when its
+ * parent context is reset via a dedicated MemoryContextCallback.
+ */
+static MemoryContext pubctx = NULL;
+
 static List *LoadPublications(List *pubnames);
 static void publication_invalidation_cb(Datum arg, int cacheid,
 										uint32 hashvalue);
@@ -253,6 +260,15 @@ parse_output_parameters(List *options, PGOutputData *data)
 }
 
 /*
+ * Callback of PGOutputData->context in charge of cleaning pubctx.
+ */
+static void
+pgoutput_pubctx_reset_callback(void *arg)
+{
+	pubctx = NULL;
+}
+
+/*
  * Initialize this plugin
  */
 static void
@@ -261,12 +277,22 @@ pgoutput_startup(LogicalDecodingContext *ctx, OutputPluginOptions *opt,
 {
 	PGOutputData *data = palloc0(sizeof(PGOutputData));
 	static bool publication_callback_registered = false;
+	MemoryContextCallback *mcallback;
 
 	/* Create our memory context for private allocations. */
 	data->context = AllocSetContextCreate(ctx->context,
 										  "logical replication output context",
 										  ALLOCSET_DEFAULT_SIZES);
 
+	Assert(pubctx == NULL);
+	pubctx = AllocSetContextCreate(ctx->context,
+								   "logical replication publication list context",
+								   ALLOCSET_SMALL_SIZES);
+
+	mcallback = palloc0(sizeof(MemoryContextCallback));
+	mcallback->func = pgoutput_pubctx_reset_callback;
+	MemoryContextRegisterResetCallback(ctx->context, mcallback);
+
 	ctx->output_plugin_private = data;
 
 	/* This plugin uses binary protocol. */
@@ -786,8 +812,9 @@ pgoutput_origin_filter(LogicalDecodingContext *ctx,
 /*
  * Shutdown the output plugin.
  *
- * Note, we don't need to clean the data->context as it's child context
- * of the ctx->context so it will be cleaned up by logical decoding machinery.
+ * Note, we don't need to clean the data->context and pubctx as they are
+ * child contexts of the ctx->context so they will be cleaned up by logical
+ * decoding machinery.
  */
 static void
 pgoutput_shutdown(LogicalDecodingContext *ctx)
@@ -797,6 +824,9 @@ pgoutput_shutdown(LogicalDecodingContext *ctx)
 		hash_destroy(RelationSyncCache);
 		RelationSyncCache = NULL;
 	}
+
+	/* Better safe than sorry */
+	pubctx = NULL;
 }
 
 /*
@@ -1071,9 +1101,10 @@ get_rel_sync_entry(PGOutputData *data, Oid relid)
 		/* Reload publications if needed before use. */
 		if (!publications_valid)
 		{
-			oldctx = MemoryContextSwitchTo(CacheMemoryContext);
-			if (data->publications)
-				list_free_deep(data->publications);
+			Assert(pubctx);
+
+			MemoryContextReset(pubctx);
+			oldctx = MemoryContextSwitchTo(pubctx);
 
 			data->publications = LoadPublications(data->publication_names);
 			MemoryContextSwitchTo(oldctx);