[ZODB-Dev] Transaction isolation levels

[Thomas Guettler]

Am Dienstag, 27. Januar 2004 19:16 schrieb Harald Koschinski:
> 2. I have a special problem with transactions - please let me explain:
>
> There is one (only one) long running (endless) request (=transaction).
> The problem now is, that objects created/deleted/changed (and committed)
> outside this transaction are not visible inside the "long runnung
> transaction".
> Is there a way to get these objects available inside the "long running
> transaction"?

Does this long running request need to be a transaction?
If not, you could do commit() several times during this request.

> I found the discussion about this topic in 3.2003 with the "read 
> committed patch" from Dieter.

May be this is what you are looking for:
From comp.lang.python.announce: ZODB2 3.3 alpha 2

The multi-version concurrency control feature represents the end of read
conflicts.  If a transaction encounters a conflict, it reads older
revisions of the object rather than raising a ReadConflictError.  This
feature allows read-only transactions to see a consistent view of the
database without need to handle read conflicts and restart the
transaction.

 thomas