af930e606a
The previous method was overly complex and underly correct; in particular, by assigning the default value with PGC_S_OVERRIDE, it prevented later attempts to change the setting in postgresql.conf, as noted by Jeff Janes. We should just assign the default value with source PGC_S_DYNAMIC_DEFAULT, which will have the desired priority relative to the boot_val as well as user-set values. There is still a gap in this method: if there's an explicit assignment of effective_cache_size = -1 in the postgresql.conf file, and that assignment appears before shared_buffers is assigned, the code will substitute 4 times the bootstrap default for shared_buffers, and that value will then persist (since it will have source PGC_S_FILE). I don't see any very nice way to avoid that though, and it's not a case to be expected in practice. The existing comments in guc-file.l look forward to a redesign of the DYNAMIC_DEFAULT mechanism; if that ever happens, we should consider this case as one of the things we'd like to improve. |
||
|---|---|---|
| config | ||
| contrib | ||
| doc | ||
| src | ||
| .dir-locals.el | ||
| .gitattributes | ||
| .gitignore | ||
| COPYRIGHT | ||
| GNUmakefile.in | ||
| HISTORY | ||
| Makefile | ||
| README | ||
| README.git | ||
| aclocal.m4 | ||
| configure | ||
| configure.in | ||
README
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: http://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.