Thread: doubts

doubts

From
"sangeetha k.s"
Date:
hello,
    
       postgresql uses bitmap indexing for indexing  in databases.
       Is there any technique used
  used to compress the bitmap indices in postgresql,like oracle that uses Byte Aligned bitmap compression to compress bitmaps.
 
regards,
sangeetha.

Re: doubts

From
Alvaro Herrera
Date:
sangeetha k.s wrote:
> hello,
>
>       postgresql uses bitmap indexing for indexing  in databases.
>       *Is there any technique used*
> *  used to compress the bitmap indices in postgresql*,like oracle that uses
> Byte Aligned bitmap compression to compress bitmaps.

Postgres does not support bitmap indexes yet.  What it does support is
bitmap index *scanning*.  And yes, there is a lossy compression method
that is sometimes used.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.