On Tue, Feb 03, 2009 at 05:48:51PM +0000, Greg Stark wrote: > On Thu, Jan 29, 2009 at 5:43 PM, David Fetter <david@xxxxxxxxxx> wrote: > >> > >> > * CTEs not yet integrated into the adjacency lists in pg_catalog, > >> > etc. > >> > >> I'm not sure what you're referring to here either. > > > > The DAG structures in pg_depend leap to mind. There's no view that > > shows the actual dependencies, except in the sense of, "Here's the > > edges. Figure it out for yourself." > > I'm trying to write some recursive queries for pg_depend and pg_locks. > I think if we come up with some nice ones we might want to add them to > the system views. Would this be a good time to revisit the idea of a pg_system_views schema? > pg_depend is actually pretty boring, you would see the same stuff if > you just did a DROP foo RESTRICT after all. Ass-u-me'ing that you have DDL permissions, which the vast majority of roles should not. > I am finding that I'm really wanting depth first searches which > would be easier to read. That would be interesting direction to > head. Depth-first searches are pretty easy to arrange with arrays. :) > pg_locks would be a *lot* more interesting imho. It's awfully hard > to decipher the pg_locks table and find the important information > buried in lots of extraneous minor locks which aren't blocking > anything. > > However I'm finding it really hard to write anything useful for > pg_locks. It seems we're missing a lot of basic info in pg_locks > and basic infrastructure to make sense of it. > > Notably, there's no indication of which lock wait queue the > ungranted locks are in. That means to find out what's blocking a > lock would require comparing every other lock to it and deciding > whether it conflicts. Interesting :) > I haven't thought hard about the pros and cons of adding more info > to pg_locks versus implementing redundant logic in SQL to mirror C > code. Neither seems terribly enticing offhand. > > I wonder if anybody else has already implemented something like > lock_conflicts()? Dunno. Could such a thing live in userland, or would it have to be compiled in? Cheers, David. -- David Fetter <david@xxxxxxxxxx> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fetter@xxxxxxxxx Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
