Insert temporary debugging output in regression tests.
We're seeing occasional instability in the plans generated for
parallel queries on the "a_star" table hierarchy. This suggests
that something is changing the planner's stats for those tables,
but that should not be happening within a regression test run.
To try to gather some information about what's happening, insert
additional queries to check the basic page/tuple counts for these
tables, as well as whether any vacuums or analyzes have happened
on them. (We expect that only the database-wide VACUUM in
sanity_check.sql will have touched them.)
I added the probes not only in select_parallel.sql itself, but
also in stats.sql, bearing in mind that the stats collector's
lag may prevent the initial query from reporting current truth.
If any extra vacuum/analyze has happened, the recheck in stats.sql
definitely ought to see it.
This commit can be reverted once we figure out what's going on.
Per suggestion from David Rowley, though I changed the queries around.
projects / postgresql / commit