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 62893221273505cf72d8e2527bbc18f9c48f774f..02b33002136ac6a5934324920cfd757279700843 100644 (file)
--- a/src/backend/executor/execReplication.c
+++ b/src/backend/executor/execReplication.c
@@ -242,6 +242,14 @@ 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
@@ -255,8 +263,6 @@ tuples_equal(TupleTableSlot *slot1, TupleTableSlot *slot2)
                if (slot1->tts_isnull[attrnum] || slot2->tts_isnull[attrnum])
                        continue;
 
-               att = TupleDescAttr(slot1->tts_tupleDescriptor, attrnum);
-
                typentry = lookup_type_cache(att->atttypid, TYPECACHE_EQ_OPR_FINFO);
                if (!OidIsValid(typentry->eq_opr_finfo.fn_oid))
                        ereport(ERROR,

diff --git a/src/test/subscription/t/100_bugs.pl b/src/test/subscription/t/100_bugs.pl
index cbf46a3d33c7a27abed1aa0f6cb78b2750200269..e1a04b1a93e406f0331fdaeea50a3b24723d7637 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 => 5;
+use Test::More tests => 6;
 
 # Bug #15114
 
@@ -179,3 +179,58 @@ 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 '$publisher_connstr_d_cols application_name=sub_dropped_cols' PUBLICATION pub_dropped_cols"
+);
+$node_subscriber_d_cols->wait_for_subscription_sync($node_publisher_d_cols,
+       'sub_dropped_cols');
+
+$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');