Explain EXPLAIN QUERY TREE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 2)
    ExpressionList (children 1)
     Function uniqCombined (children 1)
      ExpressionList (children 1)
       Function tuple (children 1)
        ExpressionList (children 1)
         Function materialize (children 1)
          ExpressionList (children 1)
           Function tuple (children 1)
            ExpressionList (children 1)
             Identifier number
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Function numbers (children 1)
        ExpressionList (children 1)
         Literal UInt64_10
