Re: Which is faster: char(14) or varchar(14)

Em 04/12/2012 18:49, Sergey Konoplev escreveu:
> On Tue, Dec 4, 2012 at 5:57 AM, Edson Richter <edsonrichter@hotmail.com> wrote:
>> In this specific case, the full length (14) is mandatory... so seems there
>> is no loss or gain.
>> Also, I see all varchar(...) created are by default "storage = EXTENDED"
>> (from "Pg Admin"), while other datatypes (like numeric, smallint, integer)
>> are "storage = MAIN".
>> Can I have a gain using fixed length datatype in place of current varchar
>> (like "numeric (14,0)")?
>> Or changing to "char(14) check length(doc)=14" and "storage=MAIN"?
> May be I am late with my reply but I would also recommend to take into
> consideration the article from depesz where he explains and tests all
> the textual types
> http://www.depesz.com/2010/03/02/charx-vs-varcharx-vs-varchar-vs-text/.
>
> Very useful one.

Yes, good education as well. I've read, and I'll consider the different
datatypes and more domain use in future.

But I don't see much changes in our schema, so using varchar(14) seems
to be as good as text.

My experience with other databases (MS SQL Server and Oracle) seems to
not apply 1:1 here (I've studied MSSQL internals and - at least up to
2005 version - is much more efficient with char than with varchar than
with text - for all operations).

Thanks again,

Edson


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