[elephant-devel] gp-export

[Leslie P. Polzer]

> helo

220 Hi there


> Just a few monthes passed, and I've made gp-export that is suitable for
> migration from 0.9 to 1.0. :)
> The problem was that there was no support for btrees whatsoever, so I had to
> refactor it badly.
> Anyway, now it seems to work and it even has some tests.

Let's put the source up somewhere.


> However, for now gp-export does not back up whole store -- it only iterates
> through all objects
> it finds in index and dumps them together with all their slots etc. It is
> such because it was meant
> to be working with various stores. (But it supports only elephant/postmodern
> so far.)

Hmm... but it will walk all class indices of the store?


> But probably if we also backup store root as some fake object instance, it
> would make full
> elephant store backup.

Yes, I think so.


> I've only made support for postmodern, if one wants it to work with BDB, he
> needs to add support.

Is this abstracted well enough?


> So, the questions are:
>    Is there a need for such thing?

Yes, considering that upgrading doesn't work too well in some cases,
needs to be written anew for every change and clutters the core code.


>    Are backups described above full/good enough?

What would be missing?


>    Should it be somehow bundled with elephant or maintained separately?

It depends on how well its components are separated from each other.

If the Elephant-specific parts can be separated easily from the rest
then we should put up the latter.


>    Are there people who'd like to hack it to add support for different
> stuff?

Like, yes. Have time for it, rather not. :/

For me it also depends on how extensible your version of gp-export is.

I'd appreciate to have the opportunity to look at the code.


>    (Well, I can do this, but I'm not very fast :) )
>
> By the way, besides gp-export, I've considered using elephant's migration
> for 0.9 to 1.0 upgrade:
>
> postmodern-0.9 --migration--> bdb-0.9 --upgrade--> bdb-1.0 --migration-->
> postmodern-1.0
>
> However, migration does not work right in version 0.9...

It does not? What errors/incorrect data did you get? Sorry if you
already posted this...

  Cheers!

    Leslie

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