I would like to know what Fractional Second Precision
is, with some examples.
And how different DBMSs support it?
sql-server Sql Server 2008 and newer has DATETIME2
which is has precision of 100ns
Character length 19 positions minimum (YYYY-MM-DD hh:mm:ss ) to 27 maximum (YYYY-MM-DD hh:mm:ss.0000000)
Precision, scale 0 to 7 digits, with an accuracy of 100ns. The default precision is 7 digits.
http://msdn.microsoft.com/en-us/library/bb677335.aspx
mysql - MySQL 5.6.4
MySQL 5.6.4 and up expands fractional seconds support for TIME, DATETIME, and TIMESTAMP values, with up to microseconds (6 digits) precision:
http://dev.mysql.com/doc/refman/5.6/en/fractional-seconds.html