Explain EXPLAIN QUERY TREE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 2)
    ExpressionList (children 1)
     Function avg (children 1)
      ExpressionList (children 1)
       Function multiply (children 1)
        ExpressionList (children 2)
         Function log (children 1)
          ExpressionList (children 1)
           Literal UInt64_2
         Identifier number
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Function numbers (children 1)
        ExpressionList (children 1)
         Literal UInt64_10
