Richard Heyes wrote: >So where's the advantage of VARCHAR ?
Less space on disc = less data retrieved from disc = faster data retrieval - sometimes. If you have small columns, a small number of rows, or both, then char columns may be faster. If you have large columns of varying actual length, lots of rows, or both, then varchar columns may be faster. The best thing for performance is reducing the number of times you hit the disc. If you can cache (more of) a table by using varchars instead of chars for some columns, then varchars have an advantage. Knowing what your data requires leads to better results than picking in advance whether to use char or varchar (or text). Measuring is even better. Oh, and for a column with a limited range of values, enum beats 'em all! -- Ross McKay, Toronto, NSW Australia "You can't control what you can't measure" - Tom DeMarco -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
