[bknr-devel] SBCL and OpenMCL ports done properly

[Hans Hübner]

Hi Kamen,

2006/2/9, Kamen TOMOV <ktomov at web.de>:

> Yeah, I know. This flexibility is great. But it would be even better
> if changes of the schema (store-objects) go into the transaction log
> as well. This way the transaction log mechanism would continue to
> work. What do you think about that?

True - But the first thing that'd need to go into the transaction log
would be the code changes.  Especially when a transaction function is
changed, the semantics of the operation changes and - if no
snapshotting is used - this change needs to be present in the
transaction log file in order to be able to successfully restore.  We
have been discussing this for quite a long time, but as our production
systems use snapshots, we presently snapshot before we do code
updates, so we don't see the lack of code change logging being a
problem.

Logging schema changes is in fact a higher order function.  The
store-object-subsystem would have to have a set of transactions that
perform the schema changes.  The general case, at least in my opinion,
is code change logging.

In the end, it would make sense to put all code into the repository
and directly edit in memory instead of using external files.  This is
kind of the long-term goal, but we have not made much progress in that
direction, sadly.

Cheers,
Hans