On Mon, Oct 21, 2024 at 2:30 PM Alexander Korotkov <aekorot...@gmail.com> wrote: > > On Mon, Oct 21, 2024 at 1:16 PM Dagfinn Ilmari Mannsåker > <ilm...@ilmari.org> wrote: > > Alexander Korotkov <aekorot...@gmail.com> writes: > > > > > On Mon, Oct 21, 2024 at 8:40 AM Andrei Lepikhov <lepi...@gmail.com> wrote: > > >> > > >> On 21/10/2024 06:32, Dagfinn Ilmari Mannsåker wrote: > > >> > Alexander Korotkov <aekorot...@gmail.com> writes: > > >> > > > >> >> +static Oid *in_progress_list; > > >> >> +static int in_progress_list_len; > > >> >> +static int in_progress_list_maxlen; > > >> > > > >> > Is there any particular reason not to use pg_list.h for this? > > >> Sure. The type cache lookup has to be as much optimal as possible. > > >> Using an array and relating sequential access to it, we avoid memory > > >> allocations and deallocations 99.9% of the time. Also, quick access to > > >> the single element (which we will have in real life almost all of the > > >> time) is much faster than employing list machinery. > > > > Lists are actually dynamically resized arrays these days (see commit > > 1cff1b95ab6ddae32faa3efe0d95a820dbfdc164), not linked lists, so > > accessing arbitrary elements is O(1), not O(n). Just like this patch, > > the size is doubled (starting at 16) whenever array is full. > > > > > +1, > > > List with zero elements has to be NIL. That means continuous > > > allocations/deallocations. > > > > This however is a valid point (unless we keep a dummy zeroth element to > > avoid it, which is even uglier than open-coding the array extension > > logic), so objection withdrawn. > > OK, thank you! > > The attached revision fixes EXTRA_INSTALL in > src/test/modules/typcache/Makefile. Spotted off-list by Arthur > Zakirov.
I've re-checked that regression tests pass with -DCLOBBER_CACHE_ALWAYS. Also did some grammar corrections for comments and commit message. I'm going to push this if no objections. ------ Regards, Alexander Korotkov Supabase
v18-0001-Update-header-comment-for-lookup_type_cache.patch
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v18-0002-Avoid-looping-over-all-type-cache-entries-in-Typ.patch
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