On Thu, Jul 1, 2010 at 11:21 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> In particular, I recall some discussions about developing a "streaming
> API" whereby an index AM could return a bitmap page-by-page or so,
> rather than having to construct the whole thing in-memory before
> anything could happen. This would be a huge win for AND/OR cases,
> and even for a simple indexscan it would eliminate the existing startup
> cost penalty for a bitmap scan. Streaming like this would also
> eliminate the problem of having to lossify large bitmaps in order to
> not overrun memory.
Now that would be cool. The existing startup penalty for a bitmap
scan is the pits.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company