[jira] [Commented] (DRILL-3518) Do a better job of providing conceptual overview to UDF creation
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https://issues.apache.org/jira/browse/DRILL-3518?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14704859#comment-14704859
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Kristine Hahn commented on DRILL-3518:
--
Doc additions: Added points 1 and 2 to [Developing a Simple
Fumction|http://kristinehahn.github.io/drill/docs/developing-a-simple-function/].
{quote}
Keep the following requirements in mind:
* Annotate all data that a UDF uses.
* Fully qualify class references.
{quote}
Added points 4 and 5 to [Developing an Aggregate
Function|http://kristinehahn.github.io/drill/docs/developing-an-aggregate-function/].
{quote}
Keep the following guidelines in mind:
* Do not use complex @Workspace variables.
* You cannot allocate a Repeated* value or have a ComplexWriter in the
@Workspace.
{quote}
These additions will appear on Apache site next time we publish.
> Do a better job of providing conceptual overview to UDF creation
>
>
> Key: DRILL-3518
> URL: https://issues.apache.org/jira/browse/DRILL-3518
> Project: Apache Drill
> Issue Type: Sub-task
> Components: Documentation
>Reporter: Jacques Nadeau
>
> Since UDFs are effectively written in Java, people find it confusing when
> some Java features aren't supported. Let's try to do a better job of
> outlining the pitfalls.
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[jira] [Commented] (DRILL-3518) Do a better job of providing conceptual overview to UDF creation
[ https://issues.apache.org/jira/browse/DRILL-3518?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14693991#comment-14693991 ] Kristine Hahn commented on DRILL-3518: -- Setting this back to Unassigned because Documentation is a broad category. Not sure if you see this being covered in the product docs, a developer blog, or the FAQ that's been suggested. The FAQs will go under the http://127.0.0.1:4000/faq/, right? > Do a better job of providing conceptual overview to UDF creation > > > Key: DRILL-3518 > URL: https://issues.apache.org/jira/browse/DRILL-3518 > Project: Apache Drill > Issue Type: Sub-task > Components: Documentation >Reporter: Jacques Nadeau > > Since UDFs are effectively written in Java, people find it confusing when > some Java features aren't supported. Let's try to do a better job of > outlining the pitfalls. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Commented] (DRILL-3518) Do a better job of providing conceptual overview to UDF creation
[ https://issues.apache.org/jira/browse/DRILL-3518?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14634262#comment-14634262 ] Ted Dunning commented on DRILL-3518: Pitfalls I have fallen into: 1) All data that a UDF uses must be annotated and must be a type that the annotation accepts 2) All class references must be fully qualified 3) It is super-easy to make a UDF that doesn't actually load and it is hard to see why (at first) 4) UDAF's can't have complex @Workspace variables because there seems to be no way to allocate even a Repeated* value, much less to have a ComplexWriter in the @Workspace 5) The annotated input, workspace and output variables have life-cycles that aren't apparent from the lexical structure of a UDAF. The fact that at add time the add() method can't see the output and that at output time both workspace and output variables are visible is confusing. 6) figuring out the maven-fu to create acceptable jars takes quite a while > Do a better job of providing conceptual overview to UDF creation > > > Key: DRILL-3518 > URL: https://issues.apache.org/jira/browse/DRILL-3518 > Project: Apache Drill > Issue Type: Sub-task > Components: Documentation >Reporter: Jacques Nadeau >Assignee: Bridget Bevens > > Since UDFs are effectively written in Java, people find it confusing when > some Java features aren't supported. Let's try to do a better job of > outlining the pitfalls. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
