March 10, 2011 at 7:53 am
In MySQL its possible to use index a prefix of a column to aid performance. is there an equivalent in SQL server?
March 10, 2011 at 8:09 am
Could be computed columns, not sure. Could you explain more what the MySQL feature is?
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
March 10, 2011 at 9:40 am
when creating an index you can filter the index key to read only N number of characters in field e.g abcdefg and not abcdeftgghhjjjjjjjjjjjjjjjjjjjjjjjjjj. I understand that when the field is used in a query there is less of an overhead.
March 10, 2011 at 10:31 am
To do that in SQL you'd need a computed column on LEFT(other column), then you'd need to filter on that computed column. Not for performance, for when you really are matching on part of the column.
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
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