Re: The speed problem of Varchar vs. Char

Josh Tolley wrote:
> On 7/8/07, Crystal <support@conceptpatterns.com> wrote:
>
>> Hi All,
>>
>> Our company need to save contact details into the PostgreSQL database. I
>> just begin to learn it, so I got many questions. I am not sure which
>> data type I should choose for website address, varchar or char. The
>> website address may be very long, and we also don't want to lose the
>> speed. Thus, the question is: if we have a large contact database, how
>> much slowdown or speed up will be expected if we choose variable length
>> rather than fixed length? Thanks forward.
>>
>> Best Wishes,
>> Crystal
>>
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>
> See http://www.postgresql.org/docs/8.2/interactive/datatype-character.html
> (or whatever the corresponding page is for the version you're using).
> Specifically, the following:
>
> Tip:  There are no performance differences between these three types,
> apart from the increased storage size when using the blank-padded
> type. While character(n) has performance advantages in some other
> database systems, it has no such advantages in PostgreSQL. In most
> situations text or character varying should be used instead.
>
> - Josh
-- Thanks a lot. Then we will use text to represent this.
>
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