Yes, modified BCD, but in Oracle's case, it is one base-100 digit per byte. In the BCD of yore, it was one decimal digit per nibble (i.e. 4 bits); works out to roughly the same thing from a storage perspective. So, each Oracle NUMBER datatype starts with the exponent (one byte) and then all remaining bytes are used to express the significant digits in base-100. Memory is kind of hazy, but I recall teaching this for the "Oracle8 Internals" seminars back in the 1998-2000 timeframe... On 6/1/2012 3:50 PM, Hans Forbrich wrote: > Yes, both number and date store each digit individually, two to a byte, > in modified Binary Coded Decimal. Sort-a tells you when the design was > locked in. If you remember BCD ... :-) > > /Hans > > On 01/06/2012 2:46 PM, Gints Plivna wrote: >> Most probably because the internal representation of Number datatype is >> muuuuuuuch different than that of char and varchar2. You can get some >> insight for example here >> http://www.ixora.com.au/notes/number_representation.htm > -- > //www.freelists.org/webpage/oracle-l -- //www.freelists.org/webpage/oracle-l