Re: Parallel Append subplan order instability on aye-aye

David Rowley <david.rowley@2ndquadrant.com> writes:
> I did add the following query just before the failing one and included
> the expected output from below.  The tests pass for me in make check
> and the post-upgrade test passes in make check-world too.  I guess we
> could commit that and see if it fails along with the other mentioned
> failure.

I'm thinking this is a good idea, although I think we could be more
aggressive about the data collected, as attached.  Since all of these
ought to be single-page tables, the relpages and reltuples counts
should be machine-independent.  In theory anyway.

            regards, tom lane

diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index 0eca76c..9775cc8 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -89,6 +89,33 @@ select round(avg(aa)), sum(aa) from a_star a3;
     14 | 355
 (1 row)

+-- Temporary hack to investigate whether extra vacuum/analyze is happening
+select relname, relpages, reltuples
+from pg_class
+where relname like '__star' order by relname;
+ relname | relpages | reltuples
+---------+----------+-----------
+ a_star  |        1 |         3
+ b_star  |        1 |         4
+ c_star  |        1 |         4
+ d_star  |        1 |        16
+ e_star  |        1 |         7
+ f_star  |        1 |        16
+(6 rows)
+
+select relname, vacuum_count, analyze_count, autovacuum_count, autoanalyze_count
+from pg_stat_all_tables
+where relname like '__star' order by relname;
+ relname | vacuum_count | analyze_count | autovacuum_count | autoanalyze_count
+---------+--------------+---------------+------------------+-------------------
+ a_star  |            1 |             0 |                0 |                 0
+ b_star  |            1 |             0 |                0 |                 0
+ c_star  |            1 |             0 |                0 |                 0
+ d_star  |            1 |             0 |                0 |                 0
+ e_star  |            1 |             0 |                0 |                 0
+ f_star  |            1 |             0 |                0 |                 0
+(6 rows)
+
 -- Disable Parallel Append
 alter table a_star reset (parallel_workers);
 alter table b_star reset (parallel_workers);
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index 03c056b..f96812b 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -36,6 +36,14 @@ explain (costs off)
   select round(avg(aa)), sum(aa) from a_star;
 select round(avg(aa)), sum(aa) from a_star a3;

+-- Temporary hack to investigate whether extra vacuum/analyze is happening
+select relname, relpages, reltuples
+from pg_class
+where relname like '__star' order by relname;
+select relname, vacuum_count, analyze_count, autovacuum_count, autoanalyze_count
+from pg_stat_all_tables
+where relname like '__star' order by relname;
+
 -- Disable Parallel Append
 alter table a_star reset (parallel_workers);
 alter table b_star reset (parallel_workers);