| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Richard Guo <guofenglinux(at)gmail(dot)com> |
| Cc: | Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, sindysenorita(at)gmail(dot)com, pgsql-bugs(at)lists(dot)postgresql(dot)org |
| Subject: | Re: BUG #17618: unnecessary filter column <> text even after adding index |
| Date: | 2022-11-07 21:06:33 |
| Message-ID: | 3495354.1667855193@sss.pgh.pa.us |
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| Lists: | pgsql-bugs |
Richard Guo <guofenglinux(at)gmail(dot)com> writes:
> I've updated the patch according to the suggestions as in v4. Thanks
> for reviewing this patch!
I was about ready to commit this when I re-read your initial comment
and realized that there's a second way to fix it. We can improve
predtest.c so that it understands that "x = true" implies "x" and
so on, whereupon the existing logic in create_bitmap_scan_plan
handles the case correctly. This is pretty nearly the same code as
in your v4, except that it's in a considerably less hot code path, plus
there's at least some chance that it could be useful for other purposes.
So I think I like this way better. Thoughts?
regards, tom lane
| Attachment | Content-Type | Size |
|---|---|---|
| v5-0001-constant-folding-for-indexquals-in-bitmap-scan.patch | text/x-diff | 4.4 KB |
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