Re: proposal: session server side variables

2017-01-04 14:33 GMT+01:00 Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>:

>
> An alternative is to implement sub (nested) transactions, like Oracle and
>> MS SQL Server... but that would be quite some work.
>>
>
> As a complement, a search showed that IBM DB2, cited as a reference by
> Pavel, has AUTONOMOUS transactions, which looks pretty much the same thing
> as nested transactions. The documentation presents an interesting use
> security-related use case:
>

I had on my mind autonomous transactions.

>
> https://www.ibm.com/developerworks/data/library/techarticle/
> dm-0907autonomoustransactions/
>
> The idea is that an application must record an attempt to access a data
> even if the attempt fails and is rolled-back.
>

Now we can this feature emulate with dblink, and there are patches in
commitfest based on background workers, and emulation will be cheaper.

Regards

Pavel

>
> This feature used carefully within an appropriate pattern would allow to
> ensure that if the setup transaction fails then the session status is
> FALSE. One possible inconsistency which may arise with sub xacts is that
> the status may stay FALSE while the setup has succeeded, however this on
> the safe side wrt to the security use case.

>
> --
> Fabien.
>