Обсуждение: pgsql: Harden pg_filenode_relation test against concurrent DROP TABLE.

Harden pg_filenode_relation test against concurrent DROP TABLE.

Per buildfarm member prairiedog.  Back-patch to 9.4, where the test was
introduced.

Reviewed by Tom Lane.

Branch
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REL9_4_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/cc3e1553fa6786b3a8c673fc9d8ce0a258ba8809

Modified Files
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src/test/regress/expected/alter_table.out |   11 ++++++++---
src/test/regress/sql/alter_table.sql      |   12 +++++++++---
2 files changed, 17 insertions(+), 6 deletions(-)