Disable synchronize_seqscans in 027_stream_regress.pl.

tglsfdc · tglsfdc · commit cbf4177f2ca0 · 2022-04-04T12:38:51.000-04:00
This script runs the core regression tests with quite a small value of shared_buffers, making it prone to breakage due to synchronize_seqscans kicking in where the tests don't expect that. Disable that feature to stabilize the tests. Discussion: https://postgr.es/m/1258185.1648876239@sss.pgh.pa.us
diff --git a/src/test/recovery/t/027_stream_regress.pl b/src/test/recovery/t/027_stream_regress.pl
@@ -16,8 +16,14 @@
 # Initialize primary node
 my $node_primary = PostgreSQL::Test::Cluster->new('primary');
 $node_primary->init(allows_streaming => 1);
+
+# Increase some settings that Cluster->new makes too low by default.
 $node_primary->adjust_conf('postgresql.conf', 'max_connections', '25');
 $node_primary->append_conf('postgresql.conf', 'max_prepared_transactions = 10');
+# We'll stick with Cluster->new's small default shared_buffers, but since that
+# makes synchronized seqscans more probable, it risks changing the results of
+# some test queries.  Disable synchronized seqscans to prevent that.
+$node_primary->append_conf('postgresql.conf', 'synchronize_seqscans = off');
 
 # WAL consistency checking is resource intensive so require opt-in with the
 # PG_TEST_EXTRA environment variable.
