Attention! rollback is significantly expensive than RESET.

I'm quite unclear about the difference... Transactional for an unshared only-in-memory session object is probably easy to implement, no WAL is needed... So I do not see the difference

you have to store previous value

This does not fully answer my question.

Maybe RESET would put NULL instead of the previous value in a rollback?

If so, I must admit that I do not see any fundamental issue with holding temporarily the initial value of an in-memory session variables so as to be able to rool it back if required...

There are no any product where variables are transactional - we should not to create wheel.

Well, AFAICS PostgreSQL GUCs are transactional.

that is exception ..

That is just logic: if you make an argument based on "it does not exist", then the argument is void if someone produces a counter example.

show me some transactiinal variables from msql, oracle, db2

I do not really know these three particular products. All I can say is that from a semantical point of view the contents of any one-row temporary relation is somehow a transactional session variable. However I do not know whether the 3 cited products have temporary tables, this is just a guess.


Sent via pgsql-hackers mailing list (
To make changes to your subscription:

Reply via email to