postgresql/src
Tom Lane 4d20bad5e9 Simplify executor's determination of whether to use parallelism.
Our parallel-mode code only works when we are executing a query
in full, so ExecutePlan must disable parallel mode when it is
asked to do partial execution.  The previous logic for this
involved passing down a flag (variously named execute_once or
run_once) from callers of ExecutorRun or PortalRun.  This is
overcomplicated, and unsurprisingly some of the callers didn't
get it right, since it requires keeping state that not all of
them have handy; not to mention that the requirements for it were
undocumented.  That led to assertion failures in some corner
cases.  The only state we really need for this is the existing
QueryDesc.already_executed flag, so let's just put all the
responsibility in ExecutePlan.  (It could have been done in
ExecutorRun too, leading to a slightly shorter patch -- but if
there's ever more than one caller of ExecutePlan, it seems better
to have this logic in the subroutine than the callers.)

This makes those ExecutorRun/PortalRun parameters unnecessary.
In master it seems okay to just remove them, returning the
API for those functions to what it was before parallelism.
Such an API break is clearly not okay in stable branches,
but for them we can just leave the parameters in place after
documenting that they do nothing.

Per report from Yugo Nagata, who also reviewed and tested
this patch.  Back-patch to all supported branches.

Discussion: https://postgr.es/m/20241206062549.710dc01cf91224809dd6c0e1@sraoss.co.jp
2024-12-09 14:38:19 -05:00
..
backend Simplify executor's determination of whether to use parallelism. 2024-12-09 14:38:19 -05:00
bin pgbench: Ensure previous progress message is fully cleared when updating. 2024-11-27 23:05:24 +09:00
common Fix overread in JSON parsing errors for incomplete byte sequences 2024-05-09 12:45:51 +09:00
fe_utils Clean up assorted failures under clang's -fsanitize=undefined checks. 2022-03-03 18:13:24 -05:00
include Simplify executor's determination of whether to use parallelism. 2024-12-09 14:38:19 -05:00
interfaces Fix broken list-munging in ecpg's remove_variables(). 2024-12-01 14:15:37 -05:00
makefiles Remove libpq.rc, use win32ver.rc for libpq 2020-01-15 15:06:12 +01:00
pl Add support for Tcl 9 2024-11-25 13:11:49 +01:00
port Fix lstat() for broken junction points on Windows. 2024-11-08 09:46:39 +10:30
template On NetBSD, force dynamic symbol resolution at postmaster start. 2022-08-30 17:29:08 -04:00
test Fix is_digit labeling of to_timestamp's FFn format codes. 2024-12-07 13:12:32 -05:00
timezone Update time zone data files to tzdata release 2024b. 2024-10-29 11:50:10 -04:00
tools Skip SectionMemoryManager.h in cpluspluscheck. 2024-11-28 15:48:52 +13:00
tutorial Doc: sync src/tutorial/basics.source with SGML documentation. 2022-11-19 13:09:14 -05:00
.gitignore
DEVELOPERS
Makefile Fix partial-build problems introduced by having more generated headers. 2018-04-09 16:42:10 -04:00
Makefile.global.in Suppress macOS warnings about duplicate libraries in link commands. 2023-09-29 14:07:30 -04:00
Makefile.shlib Stop using "-multiply_defined suppress" on macOS. 2023-09-26 21:06:21 -04:00
nls-global.mk NLS: Fix backend gettext triggers 2019-09-23 09:04:20 +02:00