SQL SELECT speed int vs varchar

Asked 2010-02-27T10:02:53.540

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I'm in the process of creating a table and it made me wonder.

If I store, say cars that has a make (fx BMW, Audi ect.), will it make any difference on the query speed if I store the make as an int or varchar.

So is

SELECT * FROM table WHERE make = 5 AND ...;

Faster/slower than

SELECT * FROM table WHERE make = 'audi' AND ...;

or will the speed be more or less the same?

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1 Answer

Index or not, int is a lot faster (the longer the varchar, the slower it gets).

Another reason: index on varchar field will be much larger than on int. For larger tables it may mean hundreds of megabytes (and thousands of pages). That makes the performance much worse as reading the index alone requires many disk reads.

answered 2010-02-27T10:33:09.183

SQL SELECT speed int vs varchar

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