http://archives.postgresql.org/pgsql-patches/2003-11/msg00363.php
In short, 5 new read-only GUC variables are created allowing the value of certain compile-time settings to be queried. Also the pg_settings system view has been expanded to include category, short_desc, and extra_desc (corresponding to group, short_desc, and long_desc in the generic guc structure). The 5 GUC variables are:
block_size - int Shows size of a disk block integer_datetimes - bool Datetimes are integer based max_function_args - int Shows the maximum number of function arguments max_identifier_length - int Shows the maximum identifier length max_index_keys - int Shows the maximum number of index keys
The main open question at this point is the name for the "block_size" variable. Peter favors "block_size", Bruce favors "page_size", Tom hasn't taken a position on that specific issue. Does anyone have and opinion on the variable name, or any general comments before I commit this?
Thanks,
Joe
regression=# select * from pg_settings where category like 'Compile%'; -[ RECORD 1 ]---------------------------------------------- name | block_size setting | 8192 category | Compiled-in Options short_desc | Shows size of a disk block extra_desc | context | internal vartype | integer source | default min_val | 8192 max_val | 8192 -[ RECORD 2 ]---------------------------------------------- name | integer_datetimes setting | on category | Compiled-in Options short_desc | Datetimes are integer based extra_desc | context | internal vartype | bool source | default min_val | max_val | -[ RECORD 3 ]---------------------------------------------- name | max_function_args setting | 32 category | Compiled-in Options short_desc | Shows the maximum number of function arguments extra_desc | context | internal vartype | integer source | default min_val | 32 max_val | 32 -[ RECORD 4 ]---------------------------------------------- name | max_identifier_length setting | 63 category | Compiled-in Options short_desc | Shows the maximum identifier length extra_desc | context | internal vartype | integer source | default min_val | 63 max_val | 63 -[ RECORD 5 ]---------------------------------------------- name | max_index_keys setting | 32 category | Compiled-in Options short_desc | Shows the maximum number of index keys extra_desc | context | internal vartype | integer source | default min_val | 32 max_val | 32
---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ?
http://www.postgresql.org/docs/faqs/FAQ.html