Re: indexing a column with only 2 or 3 values

On 3 Aug., 10:21, Helma <bad_elef..._at_hotmail.com> wrote:
> > > >>> Does indexing a very big table (about 5Mio records) on the columnA
> > > >>> which can hold only values Y,N,<NULL> make sense?
> > > >> Yes, that's what bitmap indexes were made for.
>
> FYI , you can also index only the N ( or Y) value's in the column.
> This is done if e.g. the boolean is an indicator whether a row has
> gone through a processing run or not, and the application just need to
> find the N values.
> Bitmap indexes are not ok if the table is updated intensively.
>
> Helma

Hi Helma,

It will be actually a view and will be refreshed everyday (once a day).
But thanks for the warning.

BTW. how can you index only N's for example?

chris Received on Fri Aug 03 2007 - 03:47:53 CDT