anchor.diff:      ;
   
   dataConsistencyCheckClause_
  -    : COMMA_? DATA_CONSISTENCY_CHECK EQ_ (ON | OFF)
  +    : COMMA_? DATA_CONSISTENCY_CHECK EQ_ onOffOption_
       ;
   
   historyRetentionPeriodClause_
  
positive.code:     ;
  
  onHistoryTableClause
      : LP_ HISTORY_TABLE EQ_ tableName (COMMA_ DATA_CONSISTENCY_CHECK EQ_ (ON | OFF))? RP_
      ;
  
  tableExistClause_
  
negative.code:     ;
  
  dropConstraintOption
      : (MAXDOP EQ_ NUMBER_ | ONLINE EQ_ onOffOption_ | MOVE TO (schemaName LP_ columnName RP_ | ignoredIdentifier_ | STRING_))
      ;
  
  onOffOption_
      : ON | OFF
      ;
  
  dropColumnSpecification
  