Re: Bitmap Indexes & Table Inserts

stuirvineNOstSPAM_at_hotmail.com.invalid (stuarti) wrote in <1140a557.08b68ae8_at_usw-ex0105-036.remarq.com>:

>Is there a performance hit when using bitmap indexes as oposed
>to b-tree indexes when inserting large amounts of data into a
>table ??
>

In both V8.1.5 & V8.1.6 we've seen repeatable cases where bitmap indexes grow by LARGE amounts after doing "a large number" of inserts. To quanify this generalization is that we've seen a 10 fold increase in the size of a bitmap index after doing inserts to the associated table. A DROP & CREATE of the bitmap index reduces the size back to normal. AFAIK, this is a "known problem" based upon discussion with Oracle folks.

HTH & YMMV! Received on Sun Jun 25 2000 - 00:00:00 CDT