Explain EXPLAIN PIPELINE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 4)
    ExpressionList (children 1)
     Function count (children 1)
      ExpressionList (children 1)
       Identifier JavaEnable
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier test.hits
    Function or (children 1)
     ExpressionList (children 5)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier WatchID
        Literal UInt64_1
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier Title
        Literal \'next\'
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier URL
        Literal \'prev\'
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier URL
        Literal \'???\'
      Literal UInt64_1
    Set