8.3

• Heap-Only Tuples (HOT) allow quicker re-use of the dead space left behind when a row is updated or deleted, as long as that doesn't touch its indexed columns.
• Autovacuum is turned on by default, and multiple autovacuum processes can run at once.
• You can turn off synchronous_commit in order to speed up database commits, at the expense of introducing some potential for lost transactions.
• Checkpoints can be spread over a longer period of time, adjusted using the checkpoint_completion_target setting.
• The background writer in earlier versions was easy to configure so that it decreased performance instead of improving it. The new just-in-time background writer in this version is largely automatic and has less parameters to configure.
• pg_stat_bgwriter allows monitoring both the background writer and the writes done by the spread checkpoints.
• Sequential scans use an improved scheme that reduces their memory footprint, so that they're less likely to eject useful pages from the...