On 03.07.23 07:45, Peter Eisentraut wrote:
Here is an updated patch set that adjusts for the recently introduced
named captures. I will address the other issues later. I think the
first few patches in the series can be considered nonetheless.
I have committed the 0001 patch, which was really a (code comment) bug fix.
I think the patches 0002 and 0003 should be uncontroversial, so I'd like
to commit them if no one objects.
The remaining patches are still WIP.
On 15.06.23 09:45, John Naylor wrote:
On Wed, May 31, 2023 at 4:58 AM Peter Eisentraut <pe...@eisentraut.org
<mailto:pe...@eisentraut.org>> wrote:
>
> I want to report on my on-the-plane-to-PGCon project.
>
> The idea was mentioned in [0]. genbki.pl <http://genbki.pl> already
knows everything about
> system catalog indexes. If we add a "please also make a syscache for
> this one" flag to the catalog metadata, we can have genbki.pl
<http://genbki.pl> produce
> the tables in syscache.c and syscache.h automatically.
>
> Aside from avoiding the cumbersome editing of those tables, I think
this
> layout is also conceptually cleaner, as you can more easily see which
> system catalog indexes have syscaches and maybe ask questions about
why
> or why not.
When this has come up before, one objection was that index
declarations shouldn't know about cache names and bucket sizes [1].
The second paragraph above makes a reasonable case for that, however.
I believe one alternative idea was for a script to read the enum,
which would look something like this:
#define DECLARE_SYSCACHE(cacheid,indexname,numbuckets) cacheid
enum SysCacheIdentifier
{
DECLARE_SYSCACHE(AGGFNOID, pg_aggregate_fnoid_index, 16) = 0,
...
};
...which would then look up the other info in the usual way from
Catalog.pm.
> As a possible follow-up, I have also started work on generating the
> ObjectProperty structure in objectaddress.c. One of the things you
need
> for that is making genbki.pl <http://genbki.pl> aware of the
syscache information. There
> is some more work to be done there, but it's looking promising.
I haven't studied this, but it seems interesting.
One other possible improvement: syscache.c has a bunch of #include's,
one for each catalog with a cache, so there's still a bit of manual
work in adding a cache, and the current #include list is a bit
cumbersome. Perhaps it's worth it to have the script emit them as well?
I also wonder if at some point it will make sense to split off a
separate script(s) for some things that are unrelated to the bootstrap
data. genbki.pl <http://genbki.pl> is getting pretty large, and there
are additional things that could be done with syscaches, e.g. inlined
eq/hash functions for cache lookup [2].
[1]
https://www.postgresql.org/message-id/12460.1570734...@sss.pgh.pa.us
<https://www.postgresql.org/message-id/12460.1570734...@sss.pgh.pa.us>
[2]
https://www.postgresql.org/message-id/20210831205906.4wk3s4lvgzkdaqpi%40alap3.anarazel.de <https://www.postgresql.org/message-id/20210831205906.4wk3s4lvgzkdaqpi%40alap3.anarazel.de>
--
John Naylor
EDB: http://www.enterprisedb.com <http://www.enterprisedb.com>
