On Tue, Jul 25, 2006 at 06:49:02PM -0400, Tom Lane wrote:
> What if we dropped the array convention, and simply passed the tidbitmap
> object to the index AM's getmulti function, with the instructions "stuff
> all the TIDs into this bitmap, and don't come back till you're done"?
> For the existing index AMs this'd be only trivially different, but it
> should result in some fractional savings of call overhead when scanning
> a large number of index entries.
Well, my only thoughtis that this pretty means you can't use
index_getmulti for anything else. For example, when I was playing with
async i/o I was using index_getmulti to get a list of TIDs, submitting
all the read requests in parallel and then waiting on them. What you
lose by storing straight into bitmaps is the *order*.
Mind you, index_getmulti never supported backward scans either so its
not a great loss but just thought I'd throw it in the rink.
Have a nice day,
--
Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.
