PostgreSQL 8.3.5 - Important Upgrade13 Nov 2008
Normally, minor releases just sail by… the bugs fixed are tiny things that don’t apply to your neck of the woods, but for 8.3.5 you will find this entry in the release notes:
Fix GiST index corruption due to marking the wrong index entry "dead" after a deletion (Teodor) This would result in index searches failing to find rows they should have found.
The PostGIS spatial index is built on top of GiST, so for any production table where entries are being deleted or updated, this bug could actually cause errors to crop up. Data would not be lost, but it would occasionally not be found in index-enabled searches.
If you are using PostGIS on PostgreSQL 8.3, upgrade to 8.3.5 as soon as possible. This bug has been seen in the wild, one of my clients just ran into it, it could affect you too.
Update: From Mark Cave-Ayland, the bug was only introduced during the last set of point releases, and was backpatched all the way to 8.1. So the complete list of affected PostgreSQL releases is: 8.1.14, 8.2.10 and 8.3.4. If your version is not one of those, you’re safe.