| From: | John Naylor <johncnaylorls(at)gmail(dot)com> |
|---|---|
| To: | Jeff Davis <pgsql(at)j-davis(dot)com> |
| Cc: | Andres Freund <andres(at)anarazel(dot)de>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Gurjeet Singh <gurjeet(at)singh(dot)im>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Change GUC hashtable to use simplehash? |
| Date: | 2023-12-20 06:48:22 |
| Message-ID: | CANWCAZa6QU8-pXDj2mrOhVx7c3=jws6nnhXv1FnfgTD5MXEuiQ@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Wed, Dec 20, 2023 at 3:23 AM Jeff Davis <pgsql(at)j-davis(dot)com> wrote:
>
> On Tue, 2023-12-19 at 16:23 +0700, John Naylor wrote:
> > That wasn't the next place I thought to look (that would be the
> > strcmp
> > call), but something like this could be worthwhile.
>
> The reason I looked here is that the inner while statement (to find the
> chunk size) looked out of place and possibly slow, and there's a
> bitwise trick we can use instead.
There are other bit tricks we can use. In v11-0005 Just for fun, I
translated a couple more into C from
https://github.com/openbsd/src/blob/master/lib/libc/arch/amd64/string/strlen.S
| Attachment | Content-Type | Size |
|---|---|---|
| v11-0003-Use-fasthash32-for-pgstat_hash_hash_key.patch | text/x-patch | 1.6 KB |
| v11-0002-Use-fasthash-for-the-search-path-cache.patch | text/x-patch | 2.1 KB |
| v11-0005-Optimize-tail-with-inspiration-from-OpenBSD.patch | text/x-patch | 2.4 KB |
| v11-0001-Add-inlineable-incremental-hash-functions-for-in.patch | text/x-patch | 7.9 KB |
| v11-0004-Jeff-Davis-v10jd-0004.patch | text/x-patch | 3.0 KB |
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