postgresql/contrib/postgres_fdw
Tom Lane 171c457cd0 Fix and simplify some usages of TimestampDifference().
Introduce TimestampDifferenceMilliseconds() to simplify callers
that would rather have the difference in milliseconds, instead of
the select()-oriented seconds-and-microseconds format.  This gets
rid of at least one integer division per call, and it eliminates
some apparently-easy-to-mess-up arithmetic.

Two of these call sites were in fact wrong:

* pg_prewarm's autoprewarm_main() forgot to multiply the seconds
by 1000, thus ending up with a delay 1000X shorter than intended.
That doesn't quite make it a busy-wait, but close.

* postgres_fdw's pgfdw_get_cleanup_result() thought it needed to compute
microseconds not milliseconds, thus ending up with a delay 1000X longer
than intended.  Somebody along the way had noticed this problem but
misdiagnosed the cause, and imposed an ad-hoc 60-second limit rather
than fixing the units.  This was relatively harmless in context, because
we don't care that much about exactly how long this delay is; still,
it's wrong.

There are a few more callers of TimestampDifference() that don't
have a direct need for seconds-and-microseconds, but can't use
TimestampDifferenceMilliseconds() either because they do need
microsecond precision or because they might possibly deal with
intervals long enough to overflow 32-bit milliseconds.  It might be
worth inventing another API to improve that, but that seems outside
the scope of this patch; so those callers are untouched here.

Given the fact that we are fixing some bugs, and the likelihood
that future patches might want to back-patch code that uses this
new API, back-patch to all supported branches.

Alexey Kondratov and Tom Lane

Discussion: https://postgr.es/m/3b1c053a21c07c1ed5e00be3b2b855ef@postgrespro.ru
2020-11-10 22:51:55 -05:00
..
expected In postgres_fdw, don't try to ship MULTIEXPR updates to remote server. 2020-01-26 14:31:08 -05:00
sql In postgres_fdw, don't try to ship MULTIEXPR updates to remote server. 2020-01-26 14:31:08 -05:00
.gitignore Add postgres_fdw contrib module. 2013-02-21 05:27:16 -05:00
connection.c Fix and simplify some usages of TimestampDifference(). 2020-11-10 22:51:55 -05:00
deparse.c In postgres_fdw, don't try to ship MULTIEXPR updates to remote server. 2020-01-26 14:31:08 -05:00
Makefile Prevent accidental linking of system-supplied copies of libpq.so etc. 2018-04-03 16:26:05 -04:00
option.c Update copyright for 2019 2019-01-02 12:44:25 -05:00
postgres_fdw--1.0.sql Add postgres_fdw contrib module. 2013-02-21 05:27:16 -05:00
postgres_fdw.c postgres_fdw: Fix costing of pre-sorted foreign paths with local stats. 2019-06-14 20:49:59 +09:00
postgres_fdw.control Add postgres_fdw contrib module. 2013-02-21 05:27:16 -05:00
postgres_fdw.h pgindent run prior to branching v12. 2019-07-01 12:37:52 -04:00
shippable.c Update copyright for 2019 2019-01-02 12:44:25 -05:00