[pgpool-committers: 6905] pgpool: Fix query cache bug.

[Tatsuo Ishii]

Fix query cache bug.

If EXPLAIN ANALYZE takes data-modifying SQL, it must invalidate query
cache, but actually it was missed.

Author: Hou, Zhijie
Discussion: https://www.pgpool.net/pipermail/pgpool-hackers/2020-August/003767.html

Branch
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V4_1_STABLE

Details
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https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=1b09b0013cba77386f0917de384ce425e93ef6f7

Modified Files
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src/query_cache/pool_memqcache.c                | 17 +++++++++++++++++
src/test/regression/tests/006.memqcache/test.sh |  5 +++++
2 files changed, 22 insertions(+)