[teiid-issues] [JBoss JIRA] (TEIID-1726) Requesting ability to add/use Oracle hints in EDS

[Steven Hawkins (Commented) (JIRA)]

    [ https://issues.jboss.org/browse/TEIID-1726?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12640473#comment-12640473 ] 

Steven Hawkins commented on TEIID-1726:
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I had missed your earlier question on short term advice.  Yes you can add dummy must pushdown udfs as a way to contribute a hint to the source.  Having the function in the WHERE clause is the best place to help ensure pushdown.
Something like "... WHERE CUSTOMHINT(oracle-col,'y')=1".  Note that the function or the predicate must reference a source column so that we know where to push the function to.  In that regard, this approach has a small advantage over the approach outlined in the previous comment.  The user would need to be careful to ensure that the UDF is only used in the where clause and only as a conjunct - it wouldn't make any sense to do something like "WHERE x=y OR CUSTOMHINT..."

In your augmented translator you would then modify the query criteria by removing any instance of CUSTOMHINT and then alter the getSourceComment method (assuming your starting with the Oracle or JDBCExecutionFactory).  You may even add a FunctionModifier for the hint udf(s) that would raise an exception to indicate a usage error - as it should have already been removed. 
                
> Requesting ability to add/use Oracle hints in EDS
> -------------------------------------------------
>
>                 Key: TEIID-1726
>                 URL: https://issues.jboss.org/browse/TEIID-1726
>             Project: Teiid
>          Issue Type: Feature Request
>          Components: Server
>    Affects Versions: 7.4.1
>            Reporter: Debbie Steigner
>            Assignee: Steven Hawkins
>             Fix For: 7.6
>
>
> Requesting the ability to use Oracle hints inside virtual transformations and enduser queries in EDS and Teiid Designer

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