mirror of
https://github.com/postgres/postgres.git
synced 2025-05-31 03:21:24 +03:00
ff720a597c
The planner has to special-case indexes on boolean columns, because what we need for an indexscan on such a column is a qual of the shape of "boolvar = pseudoconstant". For plain bool constants, previous simplification will have reduced this to "boolvar" or "NOT boolvar", and we have to reverse that if we want to make an indexqual. There is existing code to do so, but it only fires when the index's opfamily is BOOL_BTREE_FAM_OID or BOOL_HASH_FAM_OID. Thus extension AMs, or extension opclasses such as contrib/btree_gin, are out in the cold. The reason for hard-wiring the set of relevant opfamilies was mostly to avoid a catalog lookup in a hot code path. We can improve matters while not taking much of a performance hit by relying on the hard-wired set when the opfamily OID is visibly built-in, and only checking the catalogs when dealing with an extension opfamily. While here, rename IsBooleanOpfamily to IsBuiltinBooleanOpfamily to remind future users of that macro of its limitations. At some point we might want to make indxpath.c's improved version of the test globally accessible, but it's not presently needed elsewhere. Zongliang Quan and Tom Lane Discussion: https://postgr.es/m/f293b91d-1d46-d386-b6bb-4b06ff5c667b@yeah.net
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.