Re: indexing a column with only 2 or 3 values

> > >>> 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 Received on Fri Aug 03 2007 - 03:21:49 CDT