Hi, Sidnei da Silva wrote: > I remember having a conversation with Jim at some point where he > proposed a strategy for requests that could potentially take a long > time to finish. If I recall correctly, he proposed having a separate > ZODB connection pool. > > One thing that is problematic today is serving large files > from the ZODB (ignoring the upcoming blob support). > > a) You can't return an iterator that reads from the ZODB, because by > the time the iterator is consumed the connection has already been > closed. I believe the iterator is not consumed in the same thread, > which can cause yet more issues. > > b) If you dump the data to a temp file and return that as a file > iterator, it can potentially take twice the time. > > c) If you use RESPONSE.write() you can break other > applications. ExternalEditor comes to mind. > > d) If you just return the file as a string you can potentially run out > of memory if the file is too big. > > I would like to be able to return an iterator that can read from the > ZODB. That would probably benefit the WSGI integration as well. Anyone > has ideas about how to solve this?
I wonder whether this statement is true: Any connection handed out after the connection breaks the ACID compliance of the request. I think this is because: When finishing the actual work we have to either commit or abort the running transaction. In the time until we set up another transaction, there already might have been a change to the database by a third transaction, making the request neither isolated nor atomic. My statement is probably only true for all solutions not paying attention to the statement. ;) Christian -- gocept gmbh & co. kg - forsterstraße 29 - 06112 halle/saale - germany www.gocept.com - [EMAIL PROTECTED] - phone +49 345 122 9889 7 - fax +49 345 122 9889 1 - zope and plone consulting and development
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