Bracketed items "[]" have more detail.

Current maintainer:Bruce Momjian (pgman@candle.pha.pa.us)

Last updated:Mon Nov 815:16:11 EST 2004

Last updated:Mon Nov 822:57:34 EST 2004

The most recent version of this document can be viewed at the PostgreSQL web

site, http://www.PostgreSQL.org.

* Use mmap() rather than SYSV shared memory or to write WAL files (?) [mmap]

This would remove the requirement for SYSV SHM but would introduce

portability issues. Anonymous mmap is required to prevent I/O

overhead.

portability issues. Anonymous mmap (or mmap to /dev/zero) is required

to prevent I/O overhead.

* Consider mmap()'ing files into a backend?

Doing I/O to large tables would consume a lot of address space or

require frequent mapping/unmapping. Extending the file also causes

mapping problems that might require mapping only individual pages,

leading to thousands of mappings. Another problem is that there is no

way to _prevent_ I/O to disk from the dirty shared buffers so changes

could hit disk before WAL is written.

* Add a script to ask system configuration questions and tune postgresql.conf

* Use a phantom command counter for nested subtransactions to reduce