In commit 7012b132d0, which added support for aggregate pushdown in
postgres_fdw, the expense of evaluating the final scan/join target
computed by make_group_input_target() was not accounted for at all in
costing aggregate pushdown paths with local statistics. The right fix
for this would be to have a separate upper stage to adjust the final
scan/join relation (see comments for apply_scanjoin_target_to_paths());
but for now, fix by adding the tlist eval cost when costing aggregate
pushdown paths with local statistics.
Apply this to HEAD only to avoid destabilizing existing plan choices.
Author: Etsuro Fujita
Reviewed-By: Antonin Houska
Discussion: https://postgr.es/m/5C66A056.60007%40lab.ntt.co.jp
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.