PiMané (11/27/2012)
Hi,If a table as an index with Col1, Col2, Col3 and includes Col5, Col4, Col7 (by this order) this index is obsolete if we have another index with Col1, Col2, Col3 and includes Col4, Col5, Col6, Col7, right?
Yes.
But what about an index with Col1, Col2, Col3 compared with Col1, Col3, Col2 ?!
Is it worth having both indexes?
Maybe.
http://www.sqlservercentral.com/articles/Indexing/68636/
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability