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 108162bb356da539b47716a68b1f2add25e0af4c..f54759425b08c82d35784988dae774c28e992bfd 100644 (file)
--- a/src/backend/executor/execReplication.c
+++ b/src/backend/executor/execReplication.c
@@ -236,6 +236,14 @@ tuple_equals_slot(TupleDesc desc, HeapTuple tup, TupleTableSlot *slot)
                Form_pg_attribute att;
                TypeCacheEntry *typentry;
 
+               att = TupleDescAttr(desc, 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
@@ -249,8 +257,6 @@ tuple_equals_slot(TupleDesc desc, HeapTuple tup, TupleTableSlot *slot)
                if (isnull[attrnum])
                        continue;
 
-               att = TupleDescAttr(desc, 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 08e5f0bcb0a877516f21b37d546f4eee2d562cdf..564e099e4030d196ad2a24d2ebde0f55d6b5d61a 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
 
@@ -177,3 +177,58 @@ 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');