Hi all, >> Floating point data types are stored in an IEEE 754 binary format that >> comprises sign, exponent and mantissa. Precision is dynamic, >> corresponding to the physical storage format of the value, which may >> be up to 4 bytes for the FLOAT type and up to 8 bytes for DOUBLE >> PRECISION. > > It's exactly either 4 or 8 bytes, not "up to".
The storage used is 4 or 8 bytes, but the precision is less, because a number of bits are used for sign and exponent. FLOAT precision is 24 bits - roughly 7 decimal digits. The binary exponent's range is -126..127, which - again, roughly - corresponds to -38..38 base 10. DOUBLE precision is 53 bits (around 16 decimal digits) and the exponent ranges from -1022 to 1023 binary or roughly -308 to 308 decimal. The precision is not dynamic (except when precision is lost because the number is too small to be normalized, but I think that's outside the scope of an SQL reference). Cheers, Paul ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. http://sdm.link/zohodev2dev _______________________________________________ Firebird-docs mailing list Firebird-docs@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/firebird-docs
