Length vs precision in decimal datatype

rvw · January 5th, 2004, 12:11 PM

If I create a column with the decimal datatype, the default length is 9. The precision is set to 18 and the scale to 0. What does this mean? Is the number of bytes used by the database 9 or 18? I suppose the 0 refers to the number of characters allowed behind the comma?

joefawcett · January 5th, 2004, 12:29 PM

Precision is how many digits in total, scale is how many after decimal point/comma. Length is how many bytes of memory it occupies.

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Joe

Jeff Mason · January 5th, 2004, 12:36 PM

The precision of a decimal (or numeric) datatype is the total number of digits (both to the left and right of the decimal point) which can be stored/represented. The scale is the number of digits to the right of the decimal point. The number of bytes of storage required depends on the precision. This table gives the storage in bytes for a given range of precision values:

Code:

Precision  Bytes

1 - 9         5   
10-19         9 
20-28        13 
29-38        17

Jeff Mason
Custom Apps, Inc.
www.custom-apps.com