Andrew, there are technical barriers, such as the lack of support for parsing complex GML features. WFS-T would require parsing complex features before they could be inserted into a database. app-schema is build on simple features, and so locking would have to be coordinated with these. Furthermore, feature chaining would mean that related features would also have to be locked.
The biggest technical problem in my view is that CQL expressions are used to implement polymorphism (conditionals) and to construct data in the middleware. CQL expressions are in general irreversible. This is a huge problem in using the existing mapping as it stands. So perhaps a new mapping might be required? (Or a new ORM backend that addresses both reversibility and efficiency in one go?) One conceptual hurdle is object identity and referential integrity. When you update a complex feature, are you also updating nested properties, or just the top-level feature? What about properties that are shared between multiple features (associations)? What about multivalued attributes: do you need to garbage collect to preserve foreign key constraints? Sorry, I have more questions than answers. This is an interesting problem. :-) Kind regards, Ben. On 13/12/10 20:02, Andrew Chamberlain wrote: > Hi All, > > We were just sizing up the task of enabling transactions with the > app-schema plugin, and were wondering if anyone knew of any major issues > which might prevent / trouble the development of this? Questions which > immediately come to mind are: > > 1) Would the current mappings be re-usable, or would a separate set be > needed for the reverse (i.e. write) direction? > 2) Would such a reverse mapping be possible with the current mechanisms? > > I'm hoping that the original reason that transactions wasn't implemented > was simply a matter of limited time and funds, and not something technical. > > Any thoughts/pointers would be much appreciated. > > Best regards, > > Andy > > ------------------------------------------------------------------------------ > Oracle to DB2 Conversion Guide: Learn learn about native support for PL/SQL, > new data types, scalar functions, improved concurrency, built-in packages, > OCI, SQL*Plus, data movement tools, best practices and more. > http://p.sf.net/sfu/oracle-sfdev2dev > _______________________________________________ > Geoserver-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/geoserver-users > -- Ben Caradoc-Davies <[email protected]> Software Engineering Team Leader CSIRO Earth Science and Resource Engineering Australian Resources Research Centre ------------------------------------------------------------------------------ Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d _______________________________________________ Geoserver-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geoserver-users
