These functions are aggregates and therefore may require GROUP BY. They are the equivalent of AVG(), SUM()...
 

1 ORACLE: Tolerance

Oracle allows you to define a tolerance in many of the available SQL functions. Tolerance is used to associate a level of accuracy with geometric data. The tolerance reflects the minimum distance necessary to distinguish two points. That is, if two points are at a equal or less distance than tolerance, then they are considered the same point.

 

2 ORACLE: Arc tolerance

Oracle allows you to define a tolerance in many of the available SQL functions. Specifies for each arc in the geometry, the maximum line length. Tolerance is used to associate a level of precision with geometric data. The tolerance reflects the minimum distance required for to distinguish two points. That is, if two points are at a equal or less distance than tolerance, then they are considered the same point.