Re: [Maria-developers] WL#3859: Plug-in Service API discussion

Hi, Kristian! On Mar 11, Kristian Nielsen wrote:

Sergei Golubchik writes:

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- Will tend to discourage making desirable changes, as the procedure becomes more complicated (more work to track versioned API, less flexibitily in what C++ language constructs can be used); and there will be the desire to minimize binary incompatibility.

On the opposite, it will be easier to do changes, because versioning will make them safe and we could have old and new versions supported at the same time - that we we can add new features to a service without causing binary incompatibility with the existing plugins.

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That's the direction we want to move (and are moving) in.

Thanks for the info Sergei, that helped quite a bit.

At first I though this could introduce limitations. I am thinking for example of a thing like condition pushdown, where storage engine plugins essentially have access to the complete item tree. Having to wrap everything in item in an abstration layer doesn't seem attractive, but now I'm starting to see that it

Still that's what Timour is working on :)

does not necessarily have to be done that way. In principle under WL#3859 we could just publish an API that exposes the item tree and bump the version whenever anything changes in the implementation. (of course having a cleaner condition pushdown API could be a good thing in itself, but the important thing is that the WL#3859 interface is flexible and does not restrict anything).

Right. Regards / Mit vielen Grüßen, Sergei -- __ ___ ___ ____ __ / |/ /_ __/ __/ __ \/ / Sergei Golubchik / /|_/ / // /\ \/ /_/ / /__ Principal Software Engineer/Server Architect /_/ /_/\_, /___/\___\_\___/ Sun Microsystems GmbH, HRB München 161028 <___/ Sonnenallee 1, 85551 Kirchheim-Heimstetten Geschäftsführer: Thomas Schroeder, Wolfgang Engels, Dr. Roland Boemer Vorsitzender des Aufsichtsrates: Martin Häring