I have a MOSS publishing site. Content is quite small. I noticed that content database size is now 5GB without any significant content changes made. Using a script to show the tables' sizes, I noticed that the EventCache table size alone is over 3.5 GB. Why is this? what is the reason for this? What to do about it to reduce the size?
did you checked the following things: 1. Did you migrated your content DB from a previous version (SPS 2003)? - In this case, it might be sometimes the timerjobs to clear the eventcache table on its expiries date does not perform well and rows older than the defined number of days still remaining in the table.
Hope this may help you,
greets, Steve Chen, Support Engineer SharePoint EMEA GTSC
Try changing how many days to keep your change log and see if that table gets smaller.
Also, is your SPTimer service running correctly with the correct domain account?
Do you have a lot of users with a lot of alerts setup?