LimitOffset     PostgreSQL, MySQL (recent), SQLite
LimitXY         MySQL (older)
LimitYX         SQLite (optional)
RowsTo          InterBase/FireBird

Top             SQL/Server, MS Access
RowNum          Oracle
FetchFirst      DB2         # not implemented yet
Skip            Informix    
GenericSubQ     Sybase, plus any databases not recognised by this module

$dbh            a DBI database handle

CDBI subclass
CDBI object


%SQL::Abstract::Limit::Syntax = ( mssql    => 'Top',
                                  access   => 'Top',
                                  sybase   => 'GenericSubQ',
                                  oracle   => 'RowNum',
                                  ...