Michael Riess wrote: > Hi, > > yes, some heavily used tables contain approx. 90% free space after a > week. I'll try to increase FSM even more, but I think that I will > still have to run a full vacuum every week. Prior to 8.1 I was using > 7.4 and ran a full vacuum every day, so the autovacuum has helped a > lot. > > But actually I never understood why the database system slows down at > all when there is much unused space in the files. Are the unused pages > cached by the system, or is there another reason for the impact on the > performance? The reason is that the system needs to LOOK at the pages/tuples to see if the tuples are dead or not. So, the number of dead tuples impacts the scans. LER > > Mike -- Larry Rosenman Database Support Engineer PERVASIVE SOFTWARE. INC. 12365B RIATA TRACE PKWY 3015 AUSTIN TX 78727-6531 Tel: 512.231.6173 Fax: 512.231.6597 Email: Larry.Rosenman@xxxxxxxxxxxxx Web: www.pervasive.com
