mirror of
https://github.com/postgres/postgres.git
synced 2026-10-23 13:29:09 +03:00
7213cbfa02
The logic for asynchronous Append assumes that pending requests made for
subplans of an Append are drained during ExecReScanAppend. To ensure
that, commit 9e283fc85 modified postgresReScanForeignScan to drain such
a request if any, but failed to take into account that if such a request
was made for a subplan that is re-scanned with parameter changes or
pruned in the next round by runtime pruning, the postgres_fdw callback
function is called after ExecReScanAppend or never called, respectively.
This would cause such a request to remain even after ExecReScanAppend,
leading to incorrect results, an infinite loop, or an assertion failure.
To fix, modify ExecReScanAppend to, for each of the pending requests,
give the FDW a chance to drain that request using the existing
ForeignAsyncConfigureWait/ForeignAsyncNotify callback functions. This
makes the change made to postgresReScanForeignScan useless, so remove it
as well.
Back-patch to v14 where asynchronous Append was added.
Reported-by: Alexander Korotkov <aekorotkov@gmail.com>
Co-authored-by: Alexander Korotkov <aekorotkov@gmail.com>
Co-authored-by: Gleb Kashkin <g.kashkin@postgrespro.ru>
Co-authored-by: Etsuro Fujita <etsuro.fujita@gmail.com>
Reviewed-by: Alexander Pyhalov <a.pyhalov@postgrespro.ru>
Reviewed-by: Gleb Kashkin <g.kashkin@postgrespro.ru>
Discussion: https://postgr.es/m/CAPpHfduMOTnV5Zj2KGJ7zanL_10QvccZHtPUaDfJvBhsh9axnQ%40mail.gmail.com
Backpatch-through: 14
The PostgreSQL contrib tree
---------------------------
This subtree contains porting tools, analysis utilities, and plug-in
features that are not part of the core PostgreSQL system, mainly
because they address a limited audience or are too experimental to be
part of the main source tree. This does not preclude their
usefulness.
User documentation for each module appears in the main SGML
documentation.
When building from the source distribution, these modules are not
built automatically, unless you build the "world" target. You can
also build and install them all by running "make all" and "make
install" in this directory; or to build and install just one selected
module, do the same in that module's subdirectory.
Some directories supply new user-defined functions, operators, or
types. To make use of one of these modules, after you have installed
the code you need to register the new SQL objects in the database
system by executing a CREATE EXTENSION command. In a fresh database,
you can simply do
CREATE EXTENSION module_name;
See the PostgreSQL documentation for more information about this
procedure.