Fix handling of pgstat counters for TRUNCATE in a prepared transaction.
pgstat_twophase_postcommit is supposed to duplicate the math in
AtEOXact_PgStat, but it had missed out the bit about clearing
t_delta_live_tuples/t_delta_dead_tuples for a TRUNCATE.
It's harder than you might think to replicate the issue here, because
those counters would only be nonzero when a previous transaction in
the same backend had added/deleted tuples in the truncated table,
and those counts hadn't been sent to the stats collector yet.
Evident oversight in commit
d42358efb. I've not added a regression
test for this; we tried to add one in
d42358efb, and had to revert it
because it was too timing-sensitive for the buildfarm.
Back-patch to 9.5 where
d42358efb came in.
Stas Kelvich
Discussion: <
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