Ignore dropped columns during apply of update/delete.

We fail to apply updates and deletes when the REPLICA IDENTITY FULL is
used for the table having dropped columns. We didn't use to ignore dropped
columns while doing tuple comparison among the tuples from the publisher
and subscriber during apply of updates and deletes.

Author: Onder Kalaci, Shi yu
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CACawEhVQC9WoofunvXg12aXtbqKnEgWxoRx3+v8q32AWYsdpGg@mail.gmail.com

diff --git a/src/backend/executor/execReplication.c b/src/backend/executor/execReplication.c
index 16cab1db725b9c62619648d286ccd7d68e6dd1c1..6c3a93bd3b2ee66d1f4799ace69c04037e8ac3e3 100644 (file)
--- a/src/backend/executor/execReplication.c
+++ b/src/backend/executor/execReplication.c
@@ -243,6 +243,14 @@ tuples_equal(TupleTableSlot *slot1, TupleTableSlot *slot2,
        Form_pg_attribute att;
        TypeCacheEntry *typentry;
 
+       att = TupleDescAttr(slot1->tts_tupleDescriptor, attrnum);
+
+       /*
+        * Ignore dropped columns as the publisher doesn't send those
+        */
+       if (att->attisdropped)
+           continue;
+
        /*
         * If one value is NULL and other is not, then they are certainly not
         * equal
@@ -256,8 +264,6 @@ tuples_equal(TupleTableSlot *slot1, TupleTableSlot *slot2,
        if (slot1->tts_isnull[attrnum] || slot2->tts_isnull[attrnum])
            continue;
 
-       att = TupleDescAttr(slot1->tts_tupleDescriptor, attrnum);
-
        typentry = eq[attrnum];
        if (typentry == NULL)
        {

diff --git a/src/test/subscription/t/100_bugs.pl b/src/test/subscription/t/100_bugs.pl
index a91935e9eece4a8ce6196b51e47b31d3545ac263..a11f6be462b9d6d40173cdbbe750338e2b8a770d 100644 (file)
--- a/src/test/subscription/t/100_bugs.pl
+++ b/src/test/subscription/t/100_bugs.pl
@@ -3,7 +3,7 @@ use strict;
 use warnings;
 use PostgresNode;
 use TestLib;
-use Test::More tests => 7;
+use Test::More tests => 8;
 
 # Bug #15114
 
@@ -227,3 +227,57 @@ is( $node_subscriber->safe_psql(
 
 $node_publisher->stop('fast');
 $node_subscriber->stop('fast');
+
+# The bug was that when the REPLICA IDENTITY FULL is used with dropped columns,
+# we fail to apply updates and deletes
+my $node_publisher_d_cols = get_new_node('node_publisher_d_cols');
+$node_publisher_d_cols->init(allows_streaming => 'logical');
+$node_publisher_d_cols->start;
+
+my $node_subscriber_d_cols = get_new_node('node_subscriber_d_cols');
+$node_subscriber_d_cols->init(allows_streaming => 'logical');
+$node_subscriber_d_cols->start;
+
+$node_publisher_d_cols->safe_psql(
+   'postgres', qq(
+   CREATE TABLE dropped_cols (a int, b_drop int, c int);
+   ALTER TABLE dropped_cols REPLICA IDENTITY FULL;
+   CREATE PUBLICATION pub_dropped_cols FOR TABLE dropped_cols;
+   -- some initial data
+   INSERT INTO dropped_cols VALUES (1, 1, 1);
+));
+
+$node_subscriber_d_cols->safe_psql(
+   'postgres', qq(
+    CREATE TABLE dropped_cols (a int, b_drop int, c int);
+));
+
+my $publisher_connstr_d_cols =
+  $node_publisher_d_cols->connstr . ' dbname=postgres';
+$node_subscriber_d_cols->safe_psql('postgres',
+   "CREATE SUBSCRIPTION sub_dropped_cols CONNECTION '$publisher_connstr_d_cols' PUBLICATION pub_dropped_cols"
+);
+$node_subscriber_d_cols->wait_for_subscription_sync;
+
+$node_publisher_d_cols->safe_psql(
+   'postgres', qq(
+       ALTER TABLE dropped_cols DROP COLUMN b_drop;
+));
+$node_subscriber_d_cols->safe_psql(
+   'postgres', qq(
+       ALTER TABLE dropped_cols DROP COLUMN b_drop;
+));
+
+$node_publisher_d_cols->safe_psql(
+   'postgres', qq(
+       UPDATE dropped_cols SET a = 100;
+));
+$node_publisher_d_cols->wait_for_catchup('sub_dropped_cols');
+
+is( $node_subscriber_d_cols->safe_psql(
+       'postgres', "SELECT count(*) FROM dropped_cols WHERE a = 100"),
+   qq(1),
+   'replication with RI FULL and dropped columns');
+
+$node_publisher_d_cols->stop('fast');
+$node_subscriber_d_cols->stop('fast');