Is
it going to save space to use VARCHAR2 instead of CHAR?
Do I really get any performance
gain in Oracle if I go
for Varchar2 instead of Char
apart from the space saving....
Yes. Your space saving transalates
to more number of rows per block. This will
improve the performance of
your table scans and also give better cache
utilisation. But if you don't
compute your pctfree properly this performance
gain will be offset by row
migration ie, if these columns are updated later to
occupy more space. More number
of rows per block could also effect your
concurrency though it will
most likely be insignificant.
Denny