[OSM-dev] Field lengths in Rails port
Ævar Arnfjörð Bjarmason
avarab at gmail.com
Thu Jul 1 03:32:25 BST 2010
On Thu, Jul 1, 2010 at 01:50, John Smith <deltafoxtrot256 at gmail.com> wrote:
> On 1 July 2010 00:32, Ævar Arnfjörð Bjarmason <avarab at gmail.com> wrote:
>> Yes, but it generally handles larger types much worse than real
>> databases. E.g. you can't have an index for a TEXT, but you can index
>> VARCHAR(255) on InnoDB.
> I thought we were only discussing numeric types, but I think you can
> index varchar regardless of the DB type, and you avoid TEXT fields
> like the plague since it will use the hdd to build the query...
I was interjecting a factoid about MySQL's type handling in general as
a point of reference. And as I said the difference is that text fields
have to be VARCHAR in MySQL for it to index them, unless you use
MyISAM FULLTEXT indexes.
You don't have to avoid TEXT at all in databases that don't have such
arbitrary restrictions. PostgreSQL handles it just fine, so does
SQLite for that matter.
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