[Zope] subtransactions

[Dieter Maurer]

Chris McDonough writes:
 > Currently, yes.  This is arguably wrong.
Can you tell us, what the semantics of subtransactions is?

It has been my impression that subtransactions are a kludge,
essentially implemented for ZCatalog, to reduce the amount
of main memory for large transactions.
Rather than keep all modified objects in memory,
they are flushed onto a file to be copied from there
when the transaction is finally commited.

If this is the case, then objects that do not need
such hackery, simply provide empty "commit_sub" and
"abort_sub" and do all their work in "commit".

Dieter
 > 
 > ----- Original Message -----
 > From: "Chris Withers" <chrisw@nipltd.com>
 > To: "Chris McDonough" <chrism@digicool.com>
 > Cc: "Ian Sealy" <Ian.Sealy@bristol.ac.uk>; <zope@zope.org>
 > Sent: Friday, January 26, 2001 10:35 AM
 > Subject: Re: [Zope] subtransactions
 > 
 > 
 > > Chris McDonough wrote:
 > > >
 > > > Because most databases don't have the notion of a subtransaction.
 > >
 > > Hang on... how come, if a file upload needs to commit a subtransaction,
 > that
 > > means that an SQL method you call while processing the same request also
 > needs
 > > to support sub-transactions?
 > >
 > > confusedly,
 > >
 > > Chris
 > >
 > 
 >