How many bytes does oracle 9i use to store number datatype?

Answer 1

from <http://docs.oracle.com/cd/B19306_01/server.102/b14220/datatype.htm#i1847>

Overview of DATE Datatype

The DATE datatype stores point-in-time values (dates and times) in a table. The DATE datatype stores the year (including the century), the month, the day, the hours, the minutes, and the seconds (after midnight).

Oracle can store dates in the Julian era, ranging from January 1, 4712 BCE through December 31, 4712 CE (Common Era, or 'AD'). Unless BCE ('BC' in the format mask) is specifically used, CE date entries are the default.

Oracle uses its own internal format to store dates. Date data is stored in fixed-length fields of seven bytes each, corresponding to century, year, month, day, hour, minute, and second.

The correct answer is 7 bytes for a date column.

Answer 2

it depends on the precision and the number you are going to store. It can vary between 1 to 22 bytes.

you can use vsize function to find out how many bytes your number is stored.

select vsize(you_number_column) from your table;