| From: | Oliver Elphick <olly(at)lfix(dot)co(dot)uk> |
|---|---|
| To: | Oliver Elphick <olly(at)lfix(dot)co(dot)uk> |
| Cc: | "Samuel J(dot) Sutjiono" <ssutjiono(at)wc-group(dot)com>, pgsql-sql(at)postgresql(dot)org |
| Subject: | Re: How does Index Scan get used |
| Date: | 2002-02-22 19:32:53 |
| Message-ID: | 1014406374.13241.2406.camel@linda |
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| Lists: | pgsql-sql |
On Fri, 2002-02-22 at 18:08, Oliver Elphick wrote:
> PostgreSQL thinks there are only 10 rows in the table. Therefore it
> will not choose an index scan because for so few rows it is bound to be
> more expensive than a sequential scan.
But then I saw Tom's mail saying that it does use the index. How is
that? Surely these few values would all be brought in in one single
disk read?
--
Oliver Elphick Oliver(dot)Elphick(at)lfix(dot)co(dot)uk
Isle of Wight http://www.lfix.co.uk/oliver
GPG: 1024D/3E1D0C1C: CA12 09E0 E8D5 8870 5839 932A 614D 4C34 3E1D 0C1C
"The LORD bless thee, and keep thee; The LORD make his
face shine upon thee, and be gracious unto thee; The
LORD lift up his countenance upon thee, and give thee
peace." Numbers 6:24-26
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