This has been applied by Tom. ---------------------------------------------------------------------------
Heikki Linnakangas wrote: > Tom Lane wrote: > > "Heikki Linnakangas" <[EMAIL PROTECTED]> writes: > >> Elsewhere in our codebase where we use arrays that are enlarged as > >> needed, we keep track of the "allocated" size and the "used" size of the > >> array separately, and only call repalloc when the array fills up, and > >> repalloc a larger than necessary array when it does. I chose to just > >> call repalloc every time instead, as repalloc is smart enough to fall > >> out quickly if the chunk the allocation was made in is already larger > >> than the new size. There might be some gain avoiding the repeated > >> repalloc calls, but I doubt it's worth the code complexity, and calling > >> repalloc with a larger than necessary size can actually force it to > >> unnecessarily allocate a new, larger chunk instead of reusing the old > >> one. Thoughts on that? > > > > Seems like a pretty bad idea to me, as the behavior you're counting on > > only applies to chunks up to 8K or thereabouts. > > Oh, you're right. Though I'm sure libc realloc has all kinds of smarts > as well, it does seem better to not rely too much on that. > > > In a situation where > > you are subcommitting lots of XIDs one at a time, this is likely to have > > quite awful behavior (or at least, you're at the mercy of the local > > malloc library as to how bad it is). I'd go with the same > > double-it-each-time-needed approach we use elsewhere. > > Yep, patch attached. I also changed xactGetCommittedChildren to return > the original array instead of copying it, as Alvaro suggested. > > -- > Heikki Linnakangas > EnterpriseDB http://www.enterprisedb.com > > -- > Sent via pgsql-patches mailing list (pgsql-patches@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-patches -- Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us EnterpriseDB http://postgres.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-patches mailing list (pgsql-patches@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-patches
