----- Original Message ----- From: "John Doyle" <jdoyle(a)redhat.com&gt; To: "Steven Hawkins" <shawkins(a)redhat.com&gt; Cc: "teiid-dev" <teiid-dev(a)lists.jboss.org&gt; Sent: Wednesday, June 17, 2009 10:47:31 AM GMT -06:00 US/Canada Central Subject: Re: [teiid-dev] 6.2 planning I want to discuss the proposal to modify the connector api to produce runtime metadata objects from source metadata a bit; firstly to confirm my correct understanding and ensure that I'm understanding the full value. If I understand the proposal, the connector API would be expanded so the connector can provide the metadata of the source system via an object representation akin to JDBC metadata. This would allow a user of Teiid embedded to create bindings to source systems and query those systems without any model or VDB. Users would be able to submit queries to Teiid that joined across the source systems much like they would write in a transformation for a view model. Is all of this correct? - Yes that is correct. Unless I'm missing some additional utility of this approach, I don't really see much value in this approach. On the contrary, I think it undermines the value of Teiid by offering federation without much abstraction. I don't see how this leads to application code that significantly less brittle than what users would write without us, and I think it leads users down a dead end. Much of the code they create around this approach would likely be thrown away were they to adopt full usage of Teiid. - So you're arguing against a feature because it would lead users to adopt the full usage of Teiid? I'm not sure if I follow how that undermines Teiid.

based upon their integration needs seems more compelling than dictating a specific approach. I would also say that you're overstating the need for our abstraction. From a Java developers perspective JDO/JPA already provides a layer of abstraction between them and JDBC. To require yet another layer to perform integration is not desirable for simple integration scenarios. And it's not as if our abstraction comes for free. The most interesting scenario, an integrated updatable view, requires the use of update procedures (which have a whole host of limitations). I also think that by doing this now, we are potentially missing an opportunity to improve our integration story for community members who might want to integrate their products with Teiid. There has been a longstanding desire to reduce the effort required to create an importer, and there is also a requirement for alternative tooling. There are a lot of balls up in the air right now and I think we should take this opportunity to look at the all of APIs that we are going to expose and rationalize them as much as possible. My preferred approach would be to answer the big question first. What is our canonical representation of metadata? Is it DDL, or something else? Once we've done that, then we should define the APIs and tools to create the metadata, and the hooks to provide it. - I cannot stress enough that our persistent/command form of metadata is only indirectly related to how we would want to expose it from connectors. Also if you had a JDBC DatabaseMetadata like facility available on connectors that wouldn't that address your concern about how people can standardize importers. ~jd ----- "Steven Hawkins" <shawkins(a)redhat.com&gt; wrote: > There are three main engineering goals for the 6.2 release cycle (~12 > weeks): > To provide legacy server features to the embedded deployment, to > provide a simple client/server runtime mode, and to provide metadata > through connectors for a simple query mode. > > At a high level our requirements are: > > 1. Port the Membership, Authentication, Session, and Tracking > (CommandLogging) services for use in embedded. This is > straight-forward except for the authentication service, which will > require treating the only source for authorization information as the > vdb itself in the form of an associated xml file (note that we are not > doing something new here yet, the schema for defining policies was > introduced in 5.5.1). This is covered by TEIID-663 (with subtasks > TEIID-664 - 667) and TEIID-668. > > 2. Provide a Java main that will launch the "server" with a socket > transport. - Needs a JIRA > > 3. Ensure adminapi/admin shell coverage of all exposed functionality - > the console should not be necessary for this release. There is not a > a JIRA for this as such, but needs to be addressed as service changes > are made. > > 4. Modify the connector api to produce runtime metadata objects from > source metadata. This metadata facility will probably have a > superficial resemblance to JDBC DatadataMetadata. The QMI and other > engine logic will need to be modified to support this "modelless" > query mode. - Needs a JIRA > > The assumption with all these is that the current server mechanisms > for configuration and clustering are disregarded. We are specifically > not attempting to provide a clustered server that is feature/api > compatible with legacy MetaMatrix. This work should also have minimal > to no impact on Designer's usage of Teiid embedded. Any new work in > designer would be a stretch goal only. > > The engineering stretch goals for this release are: > > 1. Provide JOPR plugins for monitoring and additional adminapi > functionality. Van has initially indicated that he would like for > these to remain out of Teiid proper until they seem usable wrt the > release at some point much later in the cycle. > > 2. Have definitive plans around Teiid owned metadata in a persistent > form, which has already been on introduced as a topic on the > dev-list. > > 3. Re-implement file and database based artifact access through JCR > (DNA) - with an eye toward using JCR as a means to provide "cluster" > features, but that would still be api compatible with the embedded > implementation (JCR backed by the filesystem). > > 4. Refine service loading/wiring/configuration in MC or other > consistent container strategy. > > 5. Allow for pass-through ddl in both the single source and > multi-source scenarios - TEIID-669 > > In this bucket as well is a task to provide a doc set around our > legacy SOAP services and some proposed REST services in terms of how > they can be implemented with JBoss projects with a loose coupling to > Teiid. This will be covered under its own JIRA with multiple subtasks > covering prospective services use cases. > > A 6.3 bucket has been created out of pushed 6.2 items and select > issues in 6.x. This will serve as the place holder for the further > refinement of the new simplified server approach At the end of 6.3 we > should have re-established our clustering story, a good story around > configuration changes, fully incorporated JOPR, and carried-forward > any lingering server features. > > On the non-engineering side of things we have the requirements of: > > 1. Updating the server extension guide to cover things from an > embedded/simplified perspective given the changes to command logging, > membership domains, etc. > > 2. Update the connector developers guide - TEIID-104 > > 3. Add the jdbc developers guide - TEIID-315 > > There are stretch goals of: > > 1. Adding additional screen casts covering a broader set of common > uses. > > 2. Add more examples to the kit, especially highlighting use of > non-relational sources. > > 3. Get Teiid as a recognized source in other products/projects - > squirrel, dtp, hibernate, etc. > > Note there are missing JIRAs for a lot of these items and the priority > may not yet be assigned correctly for items identified as > requirements. Devs and leads should feel free to help fill in gaps. > Let me know if there is anything that has been left out or what we > should dive into a little more detail on. > > Steve > _______________________________________________ > teiid-dev mailing list > teiid-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/teiid-dev _______________________________________________ teiid-dev mailing list teiid-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/teiid-dev