Fix rare deadlock failure in create_am regression test.
The "DROP ACCESS METHOD gist2" test will require locking the index
to be dropped and then its table; while most ordinary operations
lock a table first then its index. While no concurrent test scripts
should be touching fast_emp4000, autovacuum might chance to be
processing that table when the DROP runs, resulting in a deadlock
failure. This is pretty rare but we see it in the buildfarm from
time to time.
To fix, acquire a lock on fast_emp4000 before issuing the DROP.
Since the point of the exercise is mostly to prevent buildfarm
failures, back-patch to 9.6 where this test was introduced.
Discussion: https://postgr.es/m/839004.1599185607@sss.pgh.pa.us
Branch
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REL_12_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/aa4eeb38f3aa3e4ebde4abb6edc79dd530ecda79
Modified Files
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src/test/regress/expected/create_am.out | 5 +++++
src/test/regress/sql/create_am.sql | 5 +++++
2 files changed, 10 insertions(+)