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 ab28feae2bd3d4629bd73ae3548e671c57d785f0, 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 <[email protected]>

1 files changed, 14 insertions, 0 deletions

diff --git a/contrib/test_decoding/test_decoding.c b/contrib/test_decoding/test_decoding.c
index f0b37f67fc6..a94aeeae292 100644
--- a/contrib/test_decoding/test_decoding.c
+++ b/contrib/test_decoding/test_decoding.c
@@ -101,6 +101,7 @@ pg_decode_startup(LogicalDecodingContext *ctx, OutputPluginOptions *opt,
 	ctx->output_plugin_private = data;
 
 	opt->output_type = OUTPUT_PLUGIN_TEXTUAL_OUTPUT;
+	opt->receive_rewrites = false;
 
 	foreach(option, ctx->output_plugin_options)
 	{
@@ -166,6 +167,17 @@ pg_decode_startup(LogicalDecodingContext *ctx, OutputPluginOptions *opt,
 						 errmsg("could not parse value \"%s\" for parameter \"%s\"",
 								strVal(elem->arg), elem->defname)));
 		}
+		else if (strcmp(elem->defname, "include-rewrites") == 0)
+		{
+
+			if (elem->arg == NULL)
+				continue;
+			else if (!parse_bool(strVal(elem->arg), &opt->receive_rewrites))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("could not parse value \"%s\" for parameter \"%s\"",
+								strVal(elem->arg), elem->defname)));
+		}
 		else
 		{
 			ereport(ERROR,
@@ -412,6 +424,8 @@ pg_decode_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
 						   quote_qualified_identifier(
 													  get_namespace_name(
 																		 get_rel_namespace(RelationGetRelid(relation))),
+													  class_form->relrewrite ?
+													  get_rel_name(class_form->relrewrite) :
 													  NameStr(class_form->relname)));
 	appendStringInfoChar(ctx->out, ':');