Re: [SQL] VARCHAR(50), CHAR(50) or TEXT ?

> Henrik Steffen <webmaster(at)city-map(dot)de> writes:
> > But, what is the difference between VARCHAR and TEXT ?
>
> Almost none. VARCHAR won't let you go beyond the stated maximum length,
> whereas TEXT has no specific upper limit. Otherwise they are stored
> in exactly the same way. (At least in Postgres ... dunno about other
> DBMSs.)
>
> I'd be inclined to use TEXT unless the maximum length were really an
> important part of the semantics of the data for my application. If
> you find yourself saying "Well, I *think* it'll never go beyond N
> characters, but maybe I should add a little slop for safety" then
> I'd say forget all about VARCHAR and use TEXT. If you find yourself
> saying "it *had better not* go beyond N characters, because that
> app over there will crash if it does" then use VARCHAR to enforce the
> limit.

Don't forget, char() has a performance benefit over varchar()/text.
varchar() allows you to document/clip a field to a specific lenght.
Some people like that for fixed-type fields, like "A" for active, "R"
for retired. char(1) documents it is only on character too. See the
FAQ for info on this.

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