Handle heap rewrites even better in logical decoding

Logical decoding should not publish anything about tables created as
part of a heap rewrite during DDL.  Those tables don't exist externally,
so consumers of logical decoding cannot do anything sensible with that
information.  In ab28feae2b, we worked
around this for built-in logical replication, but that was hack.

This is a more proper fix: We mark such transient heaps using the new
field pg_class.relwrite, linking to the original relation OID.  By
default, we ignore them in logical decoding before they get to the
output plugin.  Optionally, a plugin can register their interest in
getting such changes, if they handle DDL specially, in which case the
new field will help them get information about the actual table.

Reviewed-by: Craig Ringer <craig@2ndquadrant.com>

src/backend/bootstrap/bootparse.y

@@ -257,6 +257,7 @@ Boot_CreateStmt:
 													  false,
 													  true,
 													  false,
+													  InvalidOid,
 													  NULL);
 						elog(DEBUG4, "relation created with OID %u", id);
 					}

src/backend/catalog/heap.c

@@ -806,6 +806,7 @@ InsertPgClassTuple(Relation pg_class_desc,
 	values[Anum_pg_class_relispopulated - 1] = BoolGetDatum(rd_rel->relispopulated);
 	values[Anum_pg_class_relreplident - 1] = CharGetDatum(rd_rel->relreplident);
 	values[Anum_pg_class_relispartition - 1] = BoolGetDatum(rd_rel->relispartition);
+	values[Anum_pg_class_relrewrite - 1] = ObjectIdGetDatum(rd_rel->relrewrite);
 	values[Anum_pg_class_relfrozenxid - 1] = TransactionIdGetDatum(rd_rel->relfrozenxid);
 	values[Anum_pg_class_relminmxid - 1] = MultiXactIdGetDatum(rd_rel->relminmxid);
 	if (relacl != (Datum) 0)
@@ -1038,6 +1039,7 @@ heap_create_with_catalog(const char *relname,
 						 bool use_user_acl,
 						 bool allow_system_table_mods,
 						 bool is_internal,
+						 Oid relrewrite,
 						 ObjectAddress *typaddress)
 {
 	Relation	pg_class_desc;
@@ -1176,6 +1178,8 @@ heap_create_with_catalog(const char *relname,
 
 	Assert(relid == RelationGetRelid(new_rel_desc));
 
+	new_rel_desc->rd_rel->relrewrite = relrewrite;
+
 	/*
 	 * Decide whether to create an array type over the relation's rowtype. We
 	 * do not create any array types for system catalogs (ie, those made

src/backend/catalog/toasting.c

@@ -279,6 +279,7 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
 										   false,
 										   true,
 										   true,
+										   InvalidOid,
 										   NULL);
 	Assert(toast_relid != InvalidOid);
 

src/backend/commands/cluster.c

@@ -692,6 +692,7 @@ make_new_heap(Oid OIDOldHeap, Oid NewTableSpace, char relpersistence,
 										  false,
 										  true,
 										  true,
+										  OIDOldHeap,
 										  NULL);
 	Assert(OIDNewHeap != InvalidOid);
 

src/backend/commands/tablecmds.c

@@ -764,6 +764,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 										  true,
 										  allowSystemTableMods,
 										  false,
+										  InvalidOid,
 										  typaddress);
 
 	/* Store inheritance information for new rel. */

src/backend/replication/logical/logical.c

@@ -317,6 +317,8 @@ CreateInitDecodingContext(char *plugin,
 		startup_cb_wrapper(ctx, &ctx->options, true);
 	MemoryContextSwitchTo(old_context);
 
+	ctx->reorder->output_rewrites = ctx->options.receive_rewrites;
+
 	return ctx;
 }
 
@@ -410,6 +412,8 @@ CreateDecodingContext(XLogRecPtr start_lsn,
 		startup_cb_wrapper(ctx, &ctx->options, false);
 	MemoryContextSwitchTo(old_context);
 
+	ctx->reorder->output_rewrites = ctx->options.receive_rewrites;
+
 	ereport(LOG,
 			(errmsg("starting logical decoding for slot \"%s\"",
 					NameStr(slot->data.name)),

src/backend/replication/logical/reorderbuffer.c

@@ -1402,6 +1402,13 @@ ReorderBufferCommit(ReorderBuffer *rb, TransactionId xid,
 					if (!RelationIsLogicallyLogged(relation))
 						goto change_done;
 
+					/*
+					 * Ignore temporary heaps created during DDL unless the
+					 * plugin has asked for them.
+					 */
+					if (relation->rd_rel->relrewrite && !rb->output_rewrites)
+						goto change_done;
+
 					/*
 					 * For now ignore sequence changes entirely. Most of the
 					 * time they don't log changes using records we

src/backend/replication/pgoutput/pgoutput.c

@@ -21,7 +21,6 @@
 
 #include "utils/inval.h"
 #include "utils/int8.h"
-#include "utils/lsyscache.h"
 #include "utils/memutils.h"
 #include "utils/syscache.h"
 #include "utils/varlena.h"
@@ -511,31 +510,6 @@ get_rel_sync_entry(PGOutputData *data, Oid relid)
 		{
 			Publication *pub = lfirst(lc);
 
-			/*
-			 * Skip tables that look like they are from a heap rewrite (see
-			 * make_new_heap()).  We need to skip them because the subscriber
-			 * won't have a table by that name to receive the data.  That
-			 * means we won't ship the new data in, say, an added column with
-			 * a DEFAULT, but if the user applies the same DDL manually on the
-			 * subscriber, then this will work out for them.
-			 *
-			 * We only need to consider the alltables case, because such a
-			 * transient heap won't be an explicit member of a publication.
-			 */
-			if (pub->alltables)
-			{
-				char	   *relname = get_rel_name(relid);
-				unsigned int u;
-				int			n;
-
-				if (sscanf(relname, "pg_temp_%u%n", &u, &n) == 1 &&
-					relname[n] == '\0')
-				{
-					if (get_rel_relkind(u) == RELKIND_RELATION)
-						break;
-				}
-			}
-
 			if (pub->alltables || list_member_oid(pubids, pub->oid))
 			{
 				entry->pubactions.pubinsert |= pub->pubactions.pubinsert;

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201803141
+#define CATALOG_VERSION_NO	201803211
 
 #endif

src/include/catalog/heap.h

@@ -71,6 +71,7 @@ extern Oid heap_create_with_catalog(const char *relname,
 						 bool use_user_acl,
 						 bool allow_system_table_mods,
 						 bool is_internal,
+						 Oid relrewrite,
 						 ObjectAddress *typaddress);
 
 extern void heap_create_init_fork(Relation rel);

src/include/catalog/pg_class.h

@@ -70,6 +70,7 @@ CATALOG(pg_class,1259) BKI_BOOTSTRAP BKI_ROWTYPE_OID(83) BKI_SCHEMA_MACRO
 	bool		relispopulated; /* matview currently holds query results */
 	char		relreplident;	/* see REPLICA_IDENTITY_xxx constants  */
 	bool		relispartition; /* is relation a partition? */
+	Oid			relrewrite;		/* heap for rewrite during DDL, link to original rel */
 	TransactionId relfrozenxid; /* all Xids < this are frozen in this rel */
 	TransactionId relminmxid;	/* all multixacts in this rel are >= this.
 								 * this is really a MultiXactId */
@@ -98,7 +99,7 @@ typedef FormData_pg_class *Form_pg_class;
  * ----------------
  */
 
-#define Natts_pg_class						32
+#define Natts_pg_class						33
 #define Anum_pg_class_relname				1
 #define Anum_pg_class_relnamespace			2
 #define Anum_pg_class_reltype				3
@@ -126,11 +127,12 @@ typedef FormData_pg_class *Form_pg_class;
 #define Anum_pg_class_relispopulated		25
 #define Anum_pg_class_relreplident			26
 #define Anum_pg_class_relispartition		27
-#define Anum_pg_class_relfrozenxid			28
-#define Anum_pg_class_relminmxid			29
-#define Anum_pg_class_relacl				30
-#define Anum_pg_class_reloptions			31
-#define Anum_pg_class_relpartbound			32
+#define Anum_pg_class_relrewrite			28
+#define Anum_pg_class_relfrozenxid			29
+#define Anum_pg_class_relminmxid			30
+#define Anum_pg_class_relacl				31
+#define Anum_pg_class_reloptions			32
+#define Anum_pg_class_relpartbound			33
 
 /* ----------------
  *		initial contents of pg_class
@@ -145,13 +147,13 @@ typedef FormData_pg_class *Form_pg_class;
  * Note: "3" in the relfrozenxid column stands for FirstNormalTransactionId;
  * similarly, "1" in relminmxid stands for FirstMultiXactId
  */
-DATA(insert OID = 1247 (  pg_type		PGNSP 71 0 PGUID 0 0 0 0 0 0 0 f f p r 30 0 t f f f f f t n f 3 1 _null_ _null_ _null_));
+DATA(insert OID = 1247 (  pg_type		PGNSP 71 0 PGUID 0 0 0 0 0 0 0 f f p r 30 0 t f f f f f t n f 0 3 1 _null_ _null_ _null_));
 DESCR("");
-DATA(insert OID = 1249 (  pg_attribute	PGNSP 75 0 PGUID 0 0 0 0 0 0 0 f f p r 22 0 f f f f f f t n f 3 1 _null_ _null_ _null_));
+DATA(insert OID = 1249 (  pg_attribute	PGNSP 75 0 PGUID 0 0 0 0 0 0 0 f f p r 22 0 f f f f f f t n f 0 3 1 _null_ _null_ _null_));
 DESCR("");
-DATA(insert OID = 1255 (  pg_proc		PGNSP 81 0 PGUID 0 0 0 0 0 0 0 f f p r 28 0 t f f f f f t n f 3 1 _null_ _null_ _null_));
+DATA(insert OID = 1255 (  pg_proc		PGNSP 81 0 PGUID 0 0 0 0 0 0 0 f f p r 28 0 t f f f f f t n f 0 3 1 _null_ _null_ _null_));
 DESCR("");
-DATA(insert OID = 1259 (  pg_class		PGNSP 83 0 PGUID 0 0 0 0 0 0 0 f f p r 32 0 t f f f f f t n f 3 1 _null_ _null_ _null_));
+DATA(insert OID = 1259 (  pg_class		PGNSP 83 0 PGUID 0 0 0 0 0 0 0 f f p r 33 0 t f f f f f t n f 0 3 1 _null_ _null_ _null_));
 DESCR("");
 
 

src/include/replication/output_plugin.h

@@ -26,6 +26,7 @@ typedef enum OutputPluginOutputType
 typedef struct OutputPluginOptions
 {
 	OutputPluginOutputType output_type;
+	bool		receive_rewrites;
 } OutputPluginOptions;
 
 /*

src/include/replication/reorderbuffer.h

@@ -336,6 +336,11 @@ struct ReorderBuffer
 	 */
 	void	   *private_data;
 
+	/*
+	 * Saved output plugin option
+	 */
+	bool		output_rewrites;
+
 	/*
 	 * Private memory context.
 	 */