[Bizgres-general] Multi-column index support for bitmap indexes is in CVS tip

[Jie Zhang]

I have checked in changes to the CVS tip about multi-column index support
for bitmap indexes. This also includes some bug-fixes for maintaining bitmap
indexes while doing update/delete/vacuum operations.

To create a multi-column bitmap index, use the following command:

create index <index_name> on <table> using bitmap(<att1>, <att2>, ...);

This implementation will create one bitmap vector for each distinct list of
values (v1,v2,...), one for each attribute. Therefore, queries whose query
predicates have the form of "<att1>=<v1> and <att2>=<v2> and ..." will be
answered more efficiently.

You are more than welcome to check this out, and let me know if you have any
problems with this.

Thanks,
Jie