MSSQL uses an index to maintain the cluster. If a record fits between it places it there, if it doesn't, it considers either moving data or adding it physically out of order (while maintaining the index)
Kind regards/met vriendelijke groet, Serge Fonville http://www.sergefonville.nl Convince Microsoft! They need to add TRUNCATE PARTITION in SQL Server https://connect.microsoft.com/SQLServer/feedback/details/417926/truncate-partition-of-partitioned-table 2012/11/29 Mike Christensen <m...@kitchenpc.com> > > On Thu, Nov 29, 2012 at 10:28 AM, Shaun Thomas > <stho...@optionshouse.com>wrote: > >> On 11/29/2012 12:20 PM, Jeff Janes wrote: >> >> It would maintain an imperfect clustering, but still much better than >>> current behavior. >>> >> >> I thought about that, too. The "imperfect clustering" made me erase >> everything I'd written. If the clustering is imperfect, it's not really >> clustering. It would mean less random reads to restart the seek chain >> though, so it would be a perceptible gain. But it's still not real >> clustering until the order is maintained indefinitely. >> >> So far as I know, that simply can't be done with MVCC. Especially on an >> insert-only table that's clustered on a column unrelated to insert order. >> >> > How is this implemented in MS SQL then? Obviously, MS SQL supports real > clustering and has MVCC.. >
