SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 3)
    Identifier table
    Identifier partition
    Identifier active
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.parts
   Function and (children 1)
    ExpressionList (children 3)
     Function equals (children 1)
      ExpressionList (children 2)
       Identifier table
       Literal \'empty\'
     Function equals (children 1)
      ExpressionList (children 2)
       Identifier active
       Literal UInt64_1
     Function equals (children 1)
      ExpressionList (children 2)
       Identifier database
       Function currentDatabase (children 1)
        ExpressionList
