Explain EXPLAIN (children 2)
 Set
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 5)
    ExpressionList (children 1)
     Identifier day (alias s)
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier test_table
    ExpressionList (children 1)
     OrderByElement (children 1)
      Identifier s
    Literal UInt64_1
    Set