Re: PostgreSQL Indexing versus MySQL

From: Lincoln Yeoh <lyeoh(at)pop(dot)jaring(dot)my>
To: "scott(dot)marlowe" <scott(dot)marlowe(at)ihs(dot)com>, Chris Fossenier <chris(at)engenuit(dot)com>
Cc: "'Jan Wieck'" <JanWieck(at)Yahoo(dot)com>, <pgsql-general(at)postgresql(dot)org>
Subject: Re: PostgreSQL Indexing versus MySQL
Date: 2004-02-18 10:35:38
Message-ID: 5.2.1.1.1.20040218183328.0274b060@mbox.jaring.my
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At 04:14 PM 2/17/2004 -0700, scott.marlowe wrote:
>custom type (hex, foobar, etc...) from one to another. What this means
>too you, the user, is that:
>
>create table test (id int8, info text);
><insert 10,000 rows>
>select * from test where id=456;
>
>will result in a sequential scan. Why? Because the default integer type
>is int4, and your id field is int8. Cast the value to int8, and watch it
>use an index scan:
>
>select * From test where id=cast(456 as int8);

Actually won't
select * from test where id='456'
use the index?

I'm curious if this work in all cases - e.g. postgresql figures the best
cast for text to whatever, even for relevant custom types?

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