Hi Rick - yes this is useful, thanks. Just to follow up on remaining points:
- Regarding the new issue (0) I inserted in my last post: Would it be reasonable to request some sort of extension to the Table Functions set of interfaces, to provide the original SQL to Table Functions at runtime (e.g. before the initScan())? Perhaps another initScan() signature could be provided that would include the VTIEnvironment? - Also I would be interested to know what purpose the "sharedState" element of the VTIEnvironment could have? I have not found anything I could use it for in the past... - A quick note about the "com.ibm.db2j." package requirement: We have always had all our VTIs under this package for the reason you stated (certainly up to Derby 10.5). I have discovered however that with Derby 10.8, the restriction is no longer there. I believe Derby will now work with VTIs from any package. Rick> There might be a way for the Java method to dig up one of the Derby contexts and find the SQL text. However, that would not be a supported api. => It would be very useful if there was such a "context" I could grab hold of. Perhaps this context would also have a reference to the original sql as well as the function name for that particular invocation (note the same SQL can trigger multiple invocations in the case of a JOIN)... Do you have any clues on how I might get to this? We have often hoped that the VTIEnvironment would act as that kind of handle... - Thanks for the tips on StringColumnVTI, for raising the SYNONYM request and for the info on existence of VTIs in the longer term... For now I think we will have to stick with VTIs for our constructs that absolutely require dynamic table shapes - in particular our VTI class named 'GaianQuery', which takes a sub-query as argument (which may be any SQL: SELECT, CRUD, Stored Procedure...) and which is propagated through a GaianDB network of database nodes and run against any set of targeted nodes. I appreciate your help. If you are interested in finding out more about the Gaian Database, our old research release 1.5 (from 2011) is here: https://www.ibm.com/developerworks/community/groups/service/html/communityview?communityUuid=f6ce657b-f385-43b2-8350-458e6e4a344f We also have an in-house Asset release 2.1 - available on request - which has been significantly hardened. Regards David -- View this message in context: http://apache-database.10148.n7.nabble.com/Limitations-of-Table-Functions-vs-old-VTIs-tp127988p128096.html Sent from the Apache Derby Developers mailing list archive at Nabble.com.
