From 122507ca283f2f983f5113707bc067585ca8a536 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 v6 2/4] 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 b12f569702..b7b740361c 100644
--- a/src/backend/replication/logical/relation.c
+++ b/src/backend/replication/logical/relation.c
@@ -486,6 +486,40 @@ 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.
  */
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index fc210a9e7b..7c28da3714 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 7bf8cd22bd..78cd7e77f5 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 06f9215018..071a9d7b27 100644
--- a/src/test/subscription/t/013_partition.pl
+++ b/src/test/subscription/t/013_partition.pl
@@ -853,4 +853,18 @@ $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();
-- 
2.24.0.windows.2