[
https://issues.apache.org/jira/browse/DERBY-4357?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Rick Hillegas resolved DERBY-4357.
----------------------------------
Resolution: Fixed
> TableFunctions provide no information to limit underlying query
> ---------------------------------------------------------------
>
> Key: DERBY-4357
> URL: https://issues.apache.org/jira/browse/DERBY-4357
> Project: Derby
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 10.4.1.3, 10.4.2.0, 10.5.1.1, 10.5.2.0, 10.5.3.0
> Environment: ALL
> Reporter: Chris Goodacre
> Assignee: Rick Hillegas
> Attachments: derby-4357-01-aa-publicAPI.diff,
> derby-4357-02-ac-passThrough.diff, derby-4357-02-ad-passThrough.diff,
> derby-4357-03-aa-hashjoin.diff, derby-4357-04-aa-moreTests.diff,
> RestrictedTableFunctions.html, RestrictedTableFunctions.html,
> RestrictedTableFunctions.html, RestrictedTableFunctions.html,
> RestrictedTableFunctions.html
>
>
> The API specification for TableFunctions cannot provide information to the
> implementer of the TableFunction about the details of the query. For
> example:
> (a) I defined a table function named MyFunction with columns a,b, & c
> (b) I bind the table function properly using the CREATE FUNCTION SQL.
> User executes the following SQL:
> select a,b from table ( MyFunction() ) where c = 123
> Without passing the column list and/or where clause as arguments to the table
> function, my implementation can not know that it only needs two of the three
> columns, and only rows where c = 123.
> For TableFunctions that are built to integrate distant/legacy data, the cost
> of the query can be prohibitive. It would be better if information
> regarding the columns in the select and restrictions from the where clause
> could be passed to the developer.
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
https://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
