Explain EXPLAIN QUERY TREE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 4)
    ExpressionList (children 1)
     Function sum (alias j) (children 1)
      ExpressionList (children 1)
       Function minus (alias i) (children 1)
        ExpressionList (children 2)
         Literal UInt64_1
         Identifier uint64
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier test_table
    Function greater (children 1)
     ExpressionList (children 2)
      Identifier i
      Literal UInt64_0
    Function less (children 1)
     ExpressionList (children 2)
      Identifier j
      Literal UInt64_0
