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CHAR vs VARCHAR
Posted by: Richard Pupko
Date: April 19, 2012 07:13PM

Probably because of my FoxPro background, I had always thought that CHAR(n) allocated space for n characters and would pad any input to that length while VARCHAR(n) would simply store the input and perhaps truncate trailing spaces.

It seems that I have this backwards.

CREATE TEMPORARY TABLE xx (f1 CHAR(10), f2 VARCHAR(10))
INSERT INTO xx VALUES ("1","1")
INSERT INTO xx VALUES ("2 ","2 ")

SELECT LENGTH(f1),LENGTH(f2) from xx;

length(f1) Length(f2)
1 1
1 6

Is there any reason to use VARCHAR for fields shorter than 256 characters?

How is disk space calculated for CHAR and VARCHAR fields?

Is this same behavior seen in SQL-Server, Oracle, DB2, Postgres, etc?

Thanks for all responses.

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CHAR vs VARCHAR
April 19, 2012 07:13PM
April 19, 2012 08:07PM
April 20, 2012 11:32PM
April 19, 2012 08:37PM
April 20, 2012 05:52AM
April 20, 2012 10:14AM


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