Mishca, > Ummm ... not quite. In MSSQL/Sybase/Oracle, a clustered index maintains > its space saturation as part of each update operation. High activity > does indeed result in less-full pages (typically 60-80% full for tables > with heavy deletions or rowsize changes). To bring the percentage back > up, you run DBCC INDEXDEFRAG, which also does what you'd expect of a > normal file defragmenter -- put related disk pages together on the platter.
Sure, it does now, which is a nice thing. It didn't in the first version (6.5) where this cluster maint needed to be done manually and asynchronously, as I recall. > As for SQL Server being a 'single-user database' ... ummm ... no, I > don't think so. Hmmm ... perhaps it would be better if I said "serial-only database". MSSQL (like earlier versions of Sybase) handles transactions by spooling everything out to a serial log, effectively making all transcations SERIAL isolation. This has some significant benefits in performance for OLAP and data warehousing, but really kills you on high-concurrency transaction processing. > I'm REALLY happy to be shut of the Microsoft world, but > MSSQL 7/2000/2005 is a serious big DB engine. It also has some serious > bright heads behind it. They hired Goetz Graefe and Paul (aka Per-Ake) > Larsen away from academia, and it shows, in the join and aggregate > processing. I'll be a happy camper if I manage to contribute something > to PG that honks the way their stuff does. Happy to discuss, too. Yeah, they also have very speedy cursor handling. I can do things with cursors in MSSQL that I wouldn't consider with other DBs. Not that that makes up for the lack of other functionality, but it is nice when you need it. -- --Josh Josh Berkus Aglio Database Solutions San Francisco ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly