| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Amit Langote <amitlangote09(at)gmail(dot)com>, Heikki Linnakangas <hlinnaka(at)iki(dot)fi>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: making update/delete of inheritance trees scale better |
| Date: | 2021-03-31 17:37:27 |
| Message-ID: | CA+TgmoY8VBcBrwifvoi-j5tmy-2zH_wWg089TyjRGxXB=qCy3g@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Wed, Mar 31, 2021 at 1:24 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> I agree that we have some existing behavior that's related to this, but
> it's still messy, and I couldn't find any evidence that suggested that the
> runtime lookup costs anything. Typical subplans are going to deliver
> long runs of tuples from the same target relation, so as long as we
> maintain a one-element cache of the last lookup result, it's only about
> one comparison per tuple most of the time.
OK, that's pretty fair.
--
Robert Haas
EDB: http://www.enterprisedb.com
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