On Fri, Dec 10, 2010 at 12:21 PM, Daniel Loureiro <loureir...@gmail.com> wrote: >>> Most of you already know I am new to this list and newer to any OSS >>> development. However, while browsing the source code (of 9.0.1) I find >>> that there is only one way to store relations on disk - the magnetic >>> disk. > >>The fact that it's called md.c is a hangover from the '80s. These days, >>the logic that the Berkeley guys envisioned being at that code level >>is generally in kernel device drivers. md.c can drive anything that >>behaves as a block device + filesystem, which is pretty much everything >>of interest. > > I believe that PostgreSQL was been developed and optimized for > sequential access. To get full advantage of SSDs its necessary to > rewrite almost the whole project - there are so much code written with > the sequential mechanism in mind.
I don't think that that is true at all. If you tell the planner that a random page and a sequential page have the same cost, does it not believe you? Of course if you do a full table scan because their are no better options, then it scans sequentially. But you have to scan the pages in *some* order, and it is hard to see how something other than sequential would be systematically better. Cheers, Jeff -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
