pgsql: Don't truncate heap when VACUUM's failsafe is in effect.

Don't truncate heap when VACUUM's failsafe is in effect.

It seems like a good idea to bypass heap truncation when the wraparound
failsafe mechanism (which was added in commit 1e55e7d1) is in effect.

Deliberately don't bypass heap truncation in the INDEX_CLEANUP=off case,
even though it is similar to the failsafe case.  There is already a
separate reloption (and related VACUUM parameter) for that.

Reported-By: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAD21AoDWRh6oTN5T8wa+cpZUVpHXET8BJ8Da7WHVHpwkPP6KLg@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/60f1f09ff44308667ef6c72fbafd68235e55ae27

Modified Files
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src/backend/access/heap/vacuumlazy.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)