``` # show that index_b is not used $node_subscriber->poll_query_until( 'postgres', q{select idx_scan=0 from pg_stat_all_indexes where indexrelname = 'index_b';} ) or die "Timed out while waiting for check subscriber tap_sub_rep_full updates two rows via index scan with index on high cardinality column-2"; ```
poll_query_until() is still remained here, it should be replaced to is().
``` # show that the unique index on replica identity is used even when enable_indexscan=false $result = $node_subscriber->safe_psql('postgres', "select idx_scan from pg_stat_all_indexes where indexrelname = 'test_replica_id_full_idx'"); is($result, qq(0), 'ensure subscriber has not used index with enable_indexscan=false'); ```
Is the comment wrong? The index test_replica_id_full_idx is not used here.
Yeah, the comment is wrong. It is a copy & paste error from the other test. Fixed now
``` $node_publisher->safe_psql('postgres', "ALTER TABLE test_replica_id_full REPLICA IDENTITY USING INDEX test_replica_id_full_unique;"); ```
I was not sure why ALTER TABLE REPLICA IDENTITY USING INDEX was done on the publisher side. IIUC this feature works when REPLICA IDENTITY FULL is specified on a publisher, so it might not be altered here. If so, an index does not have to define on the publisher too.
Yes, not strictly necessary but it is often the case that both subscriber and publication have the similar schemas when unique index/pkey is used. For example, see t/028_row_filter.pl where we follow this pattern.
Still, I manually tried that without the index on the publisher (e.g., replica identity full), that works as expected. But given that the majority of the tests already have that approach and this test focuses on enable_indexscan, I think I'll keep it as is - unless it is confusing?
``` $node_subscriber->poll_query_until( 'postgres', q{select (idx_scan=1) from pg_stat_all_indexes where indexrelname = 'test_replica_id_full_unique'} ) or die "Timed out while waiting ensuring subscriber used unique index as replica identity even with enable_indexscan=false'"; ```
