[Bizgres-general] A bitmap index access method is available in bizgres CVS tip

[Luke Lonergan]

Mark,

On 12/19/05 7:37 PM, "Mark Kirkwood" <markir at paradise.net.nz> wrote:
> I didn't post results for creation time, but here they are (compared
> bizgres to *itself* this time). I've included the resulting index sizes too:
> btree :
>    val2  154 s, 160M    # 100 distinct
> 
> bitmap:
>    val2  224 s, 550M    # 100 distinct
> 
> So creation takes *longer* in the bitmap case - perhaps the integer data
> is the reason (let's see what happens when I try characters).

Yes - this all looks pretty yucky.  One thing I want to look at is the word
size and optimality of our bitmap compression scheme.  I presume you are
using an even distribution of values?  That is certainly a worst-case
situation, having basically no bitmap compression as it is an RLE-based
scheme.

We're looking into this now.

- Luke