VARCHAR data type, what impacts on performance?

We are using Informix On-line 4.1 on an HP9000/855. On the surface, it seems that the VARCHAR data type, if used correctly, can minimize wasted space without negatively impacting performance. Given the following situation, will I be making a mistake by converting certain columns of a table to VARCHAR? A table with about 45000 rows, row length 150 bytes. The majority of space is currently occupied by two char fields of length 60 each which are seldom filled to capacity. Neither of these fields is part of an index. Rows are inserted and deleted, but never updated. Every evening, the table's cluster index is regenerated to make sure that rows are in the optimal physical order. Any input would be most appreciated. --Glen -- Glen Gordon | Internet: ggordon@agsm.ucla.edu Computing Services | Bitnet : ggordon@uclagsm.bitnet Anderson Graduate School of Management | AT&Tnet : (310) 206-6590 University of California, Los Angeles | Fax : (310) 206-2002