necessary index

[jepatte]

What is the rule of thumb for creating an index on a Y/N column. I have a table with 15 char(1) fields with the possible value of Y or N.

My table has 2.5 million records. I need the ability to filter by any of these columns either by Y or N and sometimes other criteria regarding other fields.

Is it overkill to index each one of these or not?

 

[philhege]

Generally speaking, the fewer the unique values, the less need there is for an index on that field. In most cases, it is counterproductive.

Look up "indexes, tuning" in Books Online.

Phil Hegedusich
Senior Programmer/Analyst
IIMAK

http://www.iimak.com

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A virtual machine ate my accounting data. I transferred it to a physical box, then I beat it to smithereens with a sledgehammer. I feel better.