Simon Riggs wrote: > On Mon, 2005-08-29 at 20:25 -0400, Tom Lane wrote: > > Simon Riggs <[EMAIL PROTECTED]> writes: > > > I notice that Neil's patch regarding reducing the number of memory > > > allocations during aggregation operations isn't mentioned. It was > > > originally discussed in 8.0beta (2-3?) time. > > > > > What happened there? > > > - patch not committed in the end > > > - committed but not mentioned, as a dropped item > > > - committed but not mentioned, since part of a larger patch > > > > Are you speaking of these patches? > > Yes, those look like the ones I mentioned. > > Those seem to have a useful performance improvement? > > At very least, the change in Aggregate function API should be mentioned, > no?
> > 2005-03-12 15:25 tgl > > > > * contrib/intagg/int_aggregate.c, > > contrib/intagg/int_aggregate.sql.in, doc/src/sgml/xaggr.sgml, > > doc/src/sgml/xfunc.sgml, src/backend/executor/nodeAgg.c, > > src/backend/utils/adt/int8.c: Adjust the API for aggregate function > > calls so that a C-coded function can tell whether it is being used > > as an aggregate or not. This allows such a function to avoid > > re-pallocing a pass-by-reference transition value; normally it > > would be unsafe for a function to scribble on an input, but in the > > aggregate case it's safe to reuse the old transition value. Make > > int8inc() do this. This gets a useful improvement in the speed of > > COUNT(*), at least on narrow tables (it seems to be swamped by I/O > > when the table rows are wide). Per a discussion in early December > > with Neil Conway. I also fixed int_aggregate.c to check this, > > thereby turning it into something approaching a supportable > > technique instead of being a crude hack. I don't usually document internal API changes in the release notes. Should I? -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq