| From: | Nathan Bossart <nathandbossart(at)gmail(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | pgsql-hackers(at)lists(dot)postgresql(dot)org, alex work <alexwork033(at)gmail(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com> |
| Subject: | Re: further improving roles_is_member_of() |
| Date: | 2024-04-12 19:19:28 |
| Message-ID: | 20240412191928.GA2519977@nathanxps13 |
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| Lists: | pgsql-hackers |
On Thu, Apr 11, 2024 at 11:16:33PM -0500, Nathan Bossart wrote:
> As shown in the attached work-in-progress patch, this actually ends up
> removing more code than it adds, and it seems to provide similar results to
> HEAD (using the benchmark from the previous thread [0]). I intend to test
> it with many more roles to see if it's better in more extreme cases.
Even with 100K roles, the Bloom filter added in commit d365ae7 seems to do
a pretty good job at keeping up with the hash table approach. The callers
of roles_is_member_of() that do list_member_oid() on the returned list
might benefit a little from a hash table, but I'm skeptical it makes much
difference in practice. This was an interesting test, but I'll likely
withdraw this patch shortly.
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
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