[ 
https://issues.apache.org/jira/browse/FLINK-6334?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15995244#comment-15995244
 ] 

ASF GitHub Bot commented on FLINK-6334:
---------------------------------------

Github user fhueske commented on a diff in the pull request:

    https://github.com/apache/flink/pull/3791#discussion_r114590134
  
    --- Diff: 
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/table.scala
 ---
    @@ -93,6 +103,11 @@ class Table(
         * }}}
         */
       def select(fields: Expression*): Table = {
    +    if (UserDefinedFunctionUtils.verifyTableFunctionCallExistence(this)) {
    --- End diff --
    
    I think we can add these checks without touching all methods of `Table`.
    We could implement a method that recursively traverses a `LogicalNode` and 
checks if one of this children is an unbounded table function call. This check 
is performed in the constructor of Table and throws an exception except, the 
`logicalNode` itself is a `LogicalTableFunctionCall` (this is the case if it 
was created with the new  constructor or `as()` was applied on it.
    
    That way we can remove all checks in the methods.


> Refactoring UDTF interface
> --------------------------
>
>                 Key: FLINK-6334
>                 URL: https://issues.apache.org/jira/browse/FLINK-6334
>             Project: Flink
>          Issue Type: Improvement
>          Components: Table API & SQL
>            Reporter: Ruidong Li
>            Assignee: Ruidong Li
>            Priority: Blocker
>             Fix For: 1.3.0
>
>
> The current UDTF leverages the table.join(expression) interface, which is not 
> a proper interface in terms of semantics. We would like to refactor this to 
> let UDTF use table.join(table) interface. Very briefly,  UDTF's apply method 
> will return a Table Type, so Join(UDTF('a, 'b, ...) as 'c) shall be viewed as 
> join(Table)



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Reply via email to