2.1.2.255 T620, WINDOW clause: GROUPS option

V0291:

The specification states the following:

 Subclause 7.11, "<window clause>":
  
 <window frame units> ::=
 ROWS
 | RANGE
 | GROUPS
  
 ...
  
 Conformance Rules:
  
 Without Feature T620, "WINDOW clause: GROUPS option", conforming SQL language shall not contain <window frame units> that specifies GROUPS.

Microsoft SQL Server 2008 R2 varies as follows:

This feature is absent from the [ISO/IEC9075-2:2008] standard.

Microsoft SQL Server 2012 varies as follows:

Transact-SQL does not support this feature.