88e902b769
Commit 0bf3ae88a encountered a need to pass the finally chosen remote qual conditions forward from postgresGetForeignPlan to postgresPlanDirectModify. It solved that by sticking them into the plan node's fdw_private list, which in hindsight was a pretty bad idea. In the first place, there's no use for those qual trees either in EXPLAIN or execution; indeed they could never safely be used for any post-planning purposes, because they would not get processed by setrefs.c. So they're just dead weight to carry around in the finished plan tree, plus being an attractive nuisance for somebody who might get the idea that they could be used that way. Secondly, because those qual trees (sometimes) contained RestrictInfos, they created a plan-transmission hazard for parallel query, which is how come we noticed a problem. We dealt with that symptom in commit 28b047875, but really a more straightforward and more efficient fix is to pass the data through in a new field of struct PgFdwRelationInfo. So do it that way. (There's no need to revert 28b047875, as it has sufficient reason to live anyway.) Per fuzz testing by Andreas Seltenreich. Discussion: https://postgr.es/m/87tw5x4vcu.fsf@credativ.de
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.