Re: b-tree index performance

From: Ron Johnson <ron(dot)l(dot)johnson(at)cox(dot)net>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: b-tree index performance
Date: 2006-12-15 13:44:16
Message-ID: 4582A6B0.8000604@cox.net
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On 12/15/06 05:41, Martijn van Oosterhout wrote:
> On Fri, Dec 15, 2006 at 01:13:00PM +0200, Yonatan Ben-Nes wrote:
>> Hi all,
>>
>> I was wondering does the b-tree index performance change when it's
>> implemented on different data types fields? is it better to use one of them
>> instead of the other for (=) comparisons?
>> I'm especially interested between INT8 and TEXT data types.
>
> The difference in performence will be determined by the cost of
> comparison. The cost of comparing strings is much higher than for
> integers, so it will be slower.

And comparing INT8 is more expensive on a 32-bit system.

Since TEXT is totally variable, is there a big difference in TEXT vs
CHAR(8)?

- --
Ron Johnson, Jr.
Jefferson LA USA

Is "common sense" really valid?
For example, it is "common sense" to white-power racists that
whites are superior to blacks, and that those with brown skins
are mud people.
However, that "common sense" is obviously wrong.
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