question: private List < String > checkAllColumnsInCube ( CubeInstance cube , TableDesc table , Map < String , HiveTableMeta . HiveTableColumnMeta > fieldsMap ) { Set < ColumnDesc > usedColumns = Sets . newHashSet ( ) ; for ( TblColRef col : cube . getAllColumns ( ) ) { usedColumns . add ( col . getColumnDesc ( ) ) ; } List < String > violateColumns = Lists . newArrayList ( ) ; for ( ColumnDesc column : table . getColumns ( ) ) { if ( usedColumns . contains ( column ) ) { HiveTableMeta . HiveTableColumnMeta field = fieldsMap . get ( column . getName ( ) ) ; if ( field == null || ! isColumnCompatible ( column , field ) ) { violateColumns . add ( column . getName ( ) ) ; } } } return violateColumns ; }
target:  check whether all columns used in `cube` has compatible schema in current hive schema denoted by `fieldsMap`.