pgsql-server/ ontrib/tablefunc/README.tablefun ...

CVSROOT: /cvsroot
Module name: pgsql-server
Changes by: momjian(at)postgresql(dot)org 02/08/14 22:51:28

Modified files:
contrib/tablefunc: README.tablefunc tablefunc-test.sql
tablefunc.c tablefunc.h tablefunc.sql.in
src/backend/utils/misc: guc.c
src/bin/initdb : initdb.sh
src/include/catalog: pg_proc.h
src/include/utils: builtins.h
src/test/regress/expected: rules.out

Log message:
As discussed on several occasions previously, the new anonymous
composite type capability makes it possible to create a system view
based on a table function in a way that is hopefully palatable to
everyone. The attached patch takes advantage of this, moving
show_all_settings() from contrib/tablefunc into the backend (renamed
all_settings(). It is defined as a builtin returning type RECORD. During
initdb a system view is created to expose the same information presently
available through SHOW ALL. For example:

test=# select * from pg_settings where name like '%debug%';
name | setting
-----------------------+---------
debug_assertions | on
debug_pretty_print | off
debug_print_parse | off
debug_print_plan | off
debug_print_query | off
debug_print_rewritten | off
wal_debug | 0
(7 rows)

Additionally during initdb two rules are created which make it possible
to change settings by updating the system view -- a "virtual table" as
Tom put it. Here's an example:

Joe Conway