Re: Fragmentation opinion wanted.

> No. There is one aim with fragmentation (partitioning) and that is to > balance IO. That does not always include fragment elimination. If you > are loading data, then round robin will give you a better balance of IO > than expression based. If you have a lot of users attacking various > records, then expression based may well give a better balance of IO than > round robin. I probably should have been more verbose. Balancing I/O is only a part of it...the aim of fragmentation is efficient data access. I/O balancing by itself doesn't mean anything if you're hitting 'X' million rows unnecessarily. The physical goal of fragmentation is to achieve parallelism and/or fragment elimination, preferably both. The end result more efficient access to data via balanced I/O and/or exclusion of irrelevant data. I also think we're venturing into two different subject areas and that's: Benefits of fragmentation during loading vs. Benefits of fragmentation for data access I'd be surprised to see much in common between these two, though that obviously depends on the data content. If you're fragmenting by round-robin, then you're probably shooting for great load performance. Expression/hash fragmentation is going to impact load time, but should clean house on queries. --Chuck