From c629f16a5280a6d508ccf37bd0b91bb1b5798e69 Mon Sep 17 00:00:00 2001
From: "houzj.fnst" <houzj.fnst@cn.fujitsu.com>
Date: Mon, 13 Jun 2022 14:39:18 +0800
Subject: [PATCH] Reset partition map cache when receiving new relation mapping
 from publisher

Reset partition map cache when the publisher sends new relation mapping so
that the partition's column map can be rebuilt correctly.

---
 src/backend/replication/logical/relation.c | 34 ++++++++++++++++++++++++++++++
 src/backend/replication/logical/worker.c   |  5 +++++
 src/include/replication/logicalrelation.h  |  1 +
 src/test/subscription/t/013_partition.pl   | 14 ++++++++++++
 4 files changed, 54 insertions(+)

diff --git a/src/backend/replication/logical/relation.c b/src/backend/replication/logical/relation.c
index c1de920..decd8b2 100644
--- a/src/backend/replication/logical/relation.c
+++ b/src/backend/replication/logical/relation.c
@@ -487,6 +487,40 @@ logicalrep_partmap_invalidate_cb(Datum arg, Oid reloid)
 }
 
 /*
+ * Reset the entries in the partition map that refer to remoterel
+ *
+ * Called when new relation mapping is sent by the publisher to update our
+ * expected view of incoming data from said publisher.
+ *
+ * Note that we don't update the remoterel information in the entry here,
+ * we will update the information in logicalrep_partition_open to avoid
+ * unnecessary work.
+ */
+void
+logicalrep_partmap_reset_relmap(LogicalRepRelation *remoterel)
+{
+	HASH_SEQ_STATUS status;
+	LogicalRepPartMapEntry *part_entry;
+	LogicalRepRelMapEntry *entry;
+
+	if (LogicalRepPartMap == NULL)
+		return;
+
+	hash_seq_init(&status, LogicalRepPartMap);
+	while ((part_entry = (LogicalRepPartMapEntry *) hash_seq_search(&status)) != NULL)
+	{
+		entry = &part_entry->relmapentry;
+
+		if (entry->remoterel.remoteid != remoterel->remoteid)
+			continue;
+
+		logicalrep_relmap_free_entry(entry);
+
+		memset(entry, 0, sizeof(LogicalRepRelMapEntry));
+	}
+}
+
+/*
  * Initialize the partition map cache.
  */
 static void
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index fc210a9..7c28da3 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -1562,6 +1562,11 @@ apply_handle_relation(StringInfo s)
 
 	rel = logicalrep_read_rel(s);
 	logicalrep_relmap_update(rel);
+
+	/*
+	 * Also reset all entries in the partition map that refer to remoterel.
+	 */
+	logicalrep_partmap_reset_relmap(rel);
 }
 
 /*
diff --git a/src/include/replication/logicalrelation.h b/src/include/replication/logicalrelation.h
index 7bf8cd2..78cd7e7 100644
--- a/src/include/replication/logicalrelation.h
+++ b/src/include/replication/logicalrelation.h
@@ -38,6 +38,7 @@ typedef struct LogicalRepRelMapEntry
 } LogicalRepRelMapEntry;
 
 extern void logicalrep_relmap_update(LogicalRepRelation *remoterel);
+extern void logicalrep_partmap_reset_relmap(LogicalRepRelation *remoterel);
 
 extern LogicalRepRelMapEntry *logicalrep_rel_open(LogicalRepRelId remoteid,
 												  LOCKMODE lockmode);
diff --git a/src/test/subscription/t/013_partition.pl b/src/test/subscription/t/013_partition.pl
index 85dd7f5..1f9af6f 100644
--- a/src/test/subscription/t/013_partition.pl
+++ b/src/test/subscription/t/013_partition.pl
@@ -854,4 +854,18 @@ $result = $node_subscriber2->safe_psql('postgres',
 	"SELECT a, b, c FROM tab5 ORDER BY 1");
 is($result, qq(3|1|), 'updates of tab5 replicated correctly after altering table on subscriber');
 
+# Change the column order of table on publisher
+$node_publisher->safe_psql(
+	'postgres', q{
+	ALTER TABLE tab5 DROP COLUMN b, ADD COLUMN c INT;
+	ALTER TABLE tab5 ADD COLUMN b INT;});
+
+$node_publisher->safe_psql('postgres', "UPDATE tab5 SET c = 1 WHERE a = 3");
+
+$node_publisher->wait_for_catchup('sub2');
+
+$result = $node_subscriber2->safe_psql('postgres',
+	"SELECT a, b, c FROM tab5 ORDER BY 1");
+is($result, qq(3||1), 'updates of tab5 replicated correctly after altering table on publisher');
+
 done_testing();
-- 
2.7.2.windows.1