Re: char vs. varchar

I was told by one of my DBA instructors that whenever possible varchar should be used. Supposedly it is much quicker to read or write varchars than to retrieve or write the fixed length chars.........

BUT, one question I've always wondered about is if the system doesn't know how long a varchar is going to be, and it only allocates the space in the record for whatever the original size of the field is, then if the field length is increased doesn't the database have to store the additional characters in an overflow area of the block? In which case it would have to do MORE I/Os...

In any case, my recollection is the system is optimized to use varchars........ Received on Fri Jan 08 1999 - 20:54:00 CST