Re: index on null column

ak,

This really depends as much on how you're going to access the data as much as the content.
Will your typical query use this column in a where clause? And will it be looking for records where there is data? I did a little testing with a query which was looking for one unique value from column A and it ran much much better with an index than without. That's just one small test though. It really depends on your data and how it will be queried. If it will be looking for records that you know are null, you might play with a bitmap index.

Have fun!

>>> oramagic_at_hotmail.com 03/27/03 05:18PM >>>
I have a table with column A. there are 1000000 records in table out of which 500o records has not null in column A rest are null. if i created an index on A, will it benefit .

thanks,
ak

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