| From: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
|---|---|
| To: | André Volpato <andre(dot)volpato(at)ecomtecnologia(dot)com(dot)br> |
| Cc: | pgsql-general(at)postgresql(dot)org, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Subject: | Re: Faster data type for one-length values |
| Date: | 2007-05-23 15:22:26 |
| Message-ID: | 20070523152226.GQ4642@alvh.no-ip.org |
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| Lists: | pgsql-general |
André Volpato wrote:
> The ammount of space saved seems pretty clear to me.
Yeah, zero most of the time due to alignment.
> What are you saying is that the index behaviour is the same, for all
> types smaller than 4 bytes ? For query performance, in a search is
> based on that standalone indexed field, would be any difference using :
>
> a. char(1) ; b. int2; c. "char"
char(1) takes at least five bytes (more if the char is multibyte), so it
would be slower than the other two, ceteris paribus.
--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support
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