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Message Posted: Mon, 07 Feb 2011 @ 14:28:33 GMT
| Subj: || || Performance impact of VARCHAR size |
| From: || || Attila_Finta |
I have a question about rows per block for a table with VARCHAR columns. I have seen the Row Size Calculation Form in the TD Database Design
manual (1094). It seems that the defined length of a VARCHAR column doesn't really matter at all.
Example: a VARCHAR column currently contains values varying from 5 to 15 characters in length; if I define it as VARCHAR(200) vs. VARCHAR(20),
there will be no performance difference either way, because the only thing that matters is average size, not max. Therefore there is no penalty
to "over-sizing" VARCHAR columns. Correct?