V$SYSSTAT
displays system statistics. To find the name of the statistic associated with each statistic number (STATISTIC#
), query the V$STATNAME
view.
Column  Datatype  Description 

STATISTIC# 
NUMBER 
Statistic number
Note: Statistics numbers are not guaranteed to remain constant from one release to another. Therefore, you should rely on the statistics name rather than its number in your applications. 
NAME 
VARCHAR2(64) 
Statistic name. You can get a complete listing of statistic names by querying the V$STATNAME view. 
CLASS 
NUMBER 
A number representing one or more statistics class. The following class numbers are additive:

VALUE 
NUMBER 
Statistic value 
STAT_ID 
NUMBER 
Identifier of the statistic 