Re:

tankgirl(at)worldonline(dot)es wrote:
> Hello,
>
> I want to implement versions of a relation using production rules.
>
> I have found that the syntax for creating a version is:
>
> 'CREATE [direction] VERSION Vname FROM Bname'
>
> where...
>
> -> direction can be both forward or backward deltas
> -> Vname is the name of the version (the new table with updated,
> added or deleted tuples)
> -> Bname is the name of the base relation (the table I already have)
>
> I have typed it, but it doesn't work, and there is no man entry for
> 'CREATE VERSION'
>
> I wonder if there is any way of implementing versions using POSTGRES
> rules.
>
> Thankyou.

Hmmm, I can't find that in the grammar at all. What version
of Postgres are you using?

IIRC versioning was some feature addressed in the old
Berkeley code of Postgres, somehow related to timetravel.
Timetravel is long gone.

Maybe you can implement what you want to have with a
combination of triggers, putting some timestamps into extra
columns of your tables, and build views on top of it?

Jan

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