| From: | "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> |
|---|---|
| To: | Patrick B <patrickbakerbr(at)gmail(dot)com> |
| Cc: | pgsql-general <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: Seq scan X Index scan |
| Date: | 2017-03-08 22:41:13 |
| Message-ID: | CAKFQuwY0hvhm8hkh==dRFqhTzY8CfQL3WvaWdaO4zBHnv15Jag@mail.gmail.com |
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| Lists: | pgsql-general |
On Wed, Mar 8, 2017 at 3:32 PM, Patrick B <patrickbakerbr(at)gmail(dot)com> wrote:
> Why is SEQ SCAN faster than index scan?
>
Same number of evaluated record and less effort-per-record. You only win
with an index if you can evaluate fewer records to make up for the extra
effort per record that querying an index involves compared to just reading
the actual data.
> This is an environment t
>
> est but i'm running the same test on a production environment and also seq
> scan is cheaper than index.
>
>
Define (or show) production...
David J.
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