[ZODB-Dev] [Ann] "ReadCommitted" transaction isolation level

[Christian Reis]

On Tue, Mar 25, 2003 at 09:17:57PM +0200, Steve Alexander wrote:
> For example, a BTree object could be "locked" during a transaction that 
> reads it, so that writes by other transactions are *entirely* forbidden. 

This would be *really* interesting from the application's viewpoint
since locking critical regions inside the ZODB is today quite
impossible, as far as I know.

> It could also be locked in a more selective way, so that if the reading 
> transaction is interested in the set of BTree items where the key is 
> between 200 and 400, the BTree would be 'guarded' against inserts, 
> deletions and modifications of data where the key is between 200 and 400.

I'm not sure how an API for this could be cooked up, though.

Take care,
--
Christian Reis, Senior Engineer, Async Open Source, Brazil.
http://async.com.br/~kiko/ | [+55 16] 261 2331 | NMFL