Re: number of extents

If you drop a referential constraint and re-add it, will the new index be in one extent, or will IDS just snag the first free blocks it comes to? -- Original Message ----- From: "Christopher Coleman" <Christopher.Coleman@mediware.com> To: <informix-list@iiug.org> Sent: Wednesday, December 14, 2005 10:24 AM Subject: RE: number of extents > Bill Hamilton asked: > > Should I try to get the number of extents down on system tables? > > Also, on automatic indexes, when should you worry about how many extents > > they are in? > > Art S. Kagel responded: > > Not to worry. All system catalog tables are cached in the data dictionary > > cache so extent fragmentation in the catalog is not a problem since about > > IDS 7.1. > > I hate to disagree, but I have seen secondary effects of too many extents. One is that it can become impossible to drop a chunk because it has system catalogue extents in it. There may also occasionally be a problem when the number of extents causes other tables to become interleaved because they cannot get a sufficiently large extent. > > These are not necessarily a huge performance impact, but they can be an administrative problem. > > The reason I want to bring this up is that there is not a good, safe way to compact the system catalogue tables other than to drop and recreate the database, which is not necessarily an option. > > Sincerely, > > Christopher Coleman > > Steering Committee President > Kansas City Informix Users Group > www.iiug.org/kciug > > Database Analyst > Pharmacy Division > Mediware Information Systems, Inc. > sending to informix-list sending to informix-list