Re: plans for bitmap indexes?

Simon Riggs wrote:

>
>>I believe that the benefit of on-disk bitmap indexes is supposed to be
>>reduced storage size (compared to btree).
>>
>>    
>>
>The main problem is the need for the table to be read-only. Until we have
>partitioning, we wouldn't be able to easily guarantee parts of a table as
>being (effectively) read-only.
>
>  
>
I don't believe that read only is required. The update/insert 
performance impact of bimap indexes is however very high (in Oracle's 
implementation anyway) - to the point where many sites drop them before 
adding in new data, and recreated 'em afterwards!

In the advent that there is a benefit for the small on-disk footprint, 
the insert/update throughput implications will need to be taken into 
account.

cheers

Mark