Explain EXPLAIN SYNTAX (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 3)
     Identifier x3
     Function if (children 1)
      ExpressionList (children 3)
       Function greater (children 1)
        ExpressionList (children 2)
         Identifier x3
         Literal UInt64_10
       Identifier x3
       Function plus (children 1)
        ExpressionList (children 2)
         Identifier x1
         Identifier x2
     Function plus (children 1)
      ExpressionList (children 2)
       Identifier x1
       Identifier x2
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier test
    ExpressionList (children 1)
     OrderByElement (children 1)
      Literal Int64_-2