On 2012-11-15 11:37:16 -0500, Robert Haas wrote: > On Thu, Nov 15, 2012 at 11:22 AM, Andres Freund <and...@2ndquadrant.com> > wrote: > > On 2012-11-14 18:41:12 +0530, Abhijit Menon-Sen wrote: > >> There are two or three places in the Postgres source that implement heap > >> sort (e.g. tuplesort.c, nodeMergeAppend.c), and it's also needed by the > >> BDR code. It seemed reasonable to factor out the functionality. > > > > pg_dump also contains a binary heap implementation if memory serves > > right which makes me wonder whether we should try binaryheap.[ch] > > backend clean... It currently uses palloc/pfree. > > > > Too bad we don't have a memory allocation routine which easily works in > > the backend and frontend... palloc references MemoryContextAlloc and > > CurrentMemoryContext so thats not that easy to emulate.
> I think there's a clear need for a library of code that can be shared > by frontend and backend code. I don't necessarily want to punt > everything into libpq, though. Aggreed. > What I wonder if we might do is create > something like src/lib/pgguts that contains routines for memory > allocation, error handling, stringinfos (so that you don't have to use > PQexpBuffer in the frontend and StringInfo in the backend), etc. and > make that usable by both front-end and back-end code. I think that > would be a tremendously nice thing to have. Yes. But it also sounds like quite a bit of work :( > I don't think we should make it this patch's problem to do that Me neither. I was thinking about letting the "user" allocate enough memory like: binaryheap *heap = palloc(binaryheap_size(/*capacity*/ 10)); binaryheap_init(heap, 10, comparator); But thats pretty ugly. > but > I'd be strongly in favor of such a thing if someone wants to put it > together. It's been a huge nuisance for me in the past and all > indicates are that the work you're doing on LR is just going to > exacerbate that problem. I actually hope I won't have to fight with that all that much, but we will see :/ Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers