On Mon, Feb 22, 2010 at 8:18 AM, Gokulakannan Somasundaram <gokul...@gmail.com> wrote: > a) IOT has both table and index in one structure. So no duplication of data > b) With visibility maps, we have three structures a) Table b) Index c) > Visibility map. So the disk footprint of the same data will be higher in > postgres ( 2x + size of the visibility map).
These sound like the same point to me. I don't think we're concerned with footprint -- only with how much of that footprint actually needs to be scanned. So if we have a solution allowing the scan to only need to look at the index then the extra footprint of the table doesn't cost anything at run-time. And the visibility map is very small. I think you would be better off looking for incremental improvements rather than major architectural changes like having no heap for a table. There are so many design decisions hinged on having a heap that it would be impractical to rethink them all. -- greg -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
