Re: Question about VARCHAR Vs. CHAR fields

"DA Morgan" <damorgan@psoug.org> wrote > Is it true that in Informix VARCHAR takes more space than CHAR? Not at all. Just one byte extra at the beginning to record the length. > In Oracle the waste of space and CPU comes with working with CHAR and > it has been almost completely abandoned. same is true with informix, except that upto a length of char(15) (some say even 20) the performance gain in char is worth the space wasted. so I would always recommend a char field upto char(15). The difference between char and varchar becomes stark in delete-and-load tables. That is tables which are periodically cleaned and loaded again. A table with fixed-length columns (char, int, date etc) loads much faster than with variable length table. I think it is something to do with the engine calculating before inserting on which page the row will fit.