-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Etienne Labuschagne wrote: > On 7/11/05, Florent Guillaume <[EMAIL PROTECTED]> wrote: > >>ZODB versions are deprecated, unsupported, buggy and hard to use. Don't >>use them. >> >>Florent > > > And as I understand, so are temporary connections too. That leaves me > with getting a "normal" ZODB connection from the pool which I don't > want to do. > > I really need a "temporary" connection that I can discard. This > connection can have a much smaller cache than the normal connections > as it makes very little difference in the speed of data loading. > Second prize is a connection that will only be used by a specific > process and never used for other processes. Versions solves this for > me. > > I can check out a connection and keep it aside only for data loading. > But this means that I waste precious memory on a connection that does > not really need to cache the amount of objects that the other > connections should. In my case, this translates to using 1GB of RAM > on one connection that gets used once a day. > > Please believe me that I really need a "special" connection. For > those who really want to know why, below is an attempt at an > explanation why: > > In the application that I have written, I want to be able to get > connections that are not part of the normal connection pool. Once my > process is finished, I can store these connections for later use, or > discard them. Currently my application uses the normal connections in > the pool. The problem is that this process "contaminates" the cache > of the connections with objects that are not used in "normal" client > application use (I use a thick client). This means that the client > applications are extremely slow the next day and that it takes a long > time before the cache contains the often used objects again. > >>From there the reason why I DON'T want to use the connections for my > once a day data loading process. > > My ZODB contains about 700`000 objects. A connection caches about > 60`000 objects to give satisfactory client speed. To start up the > client before the cache is initialized, takes about 5 minutes. Once > the cache is populated, it takes a client seconds to start up. Data > loading invalidates all of this, but is worse than a "clean" cache in > that it takes long for the "new" objects in the cache to be flushed > and replaced by the often used objects again. Data loading does not > need such a big cache since it mostly loads data into the ZODB. > Unfortunately, the loaded objects also end up in the cache. > > Why do I need so many objects in the cache? Some searches cannot be > done with a mere ZCatalog search and have to run through a subset of > all the objects. These tend to fit nicely in the cache.
Your query would be better served on the zodb-dev list, where Tim Peters hangs out; he can probably explain how to get what you want without guessing. If I had to guess, I would suggest constructing your connection programmatically, where you can specify the object cache size for instance, and then closing / discarding the connection when you are done. Tres. - -- =================================================================== Tres Seaver +1 202-558-7113 [EMAIL PROTECTED] Palladion Software "Excellence by Design" http://palladion.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFC0p6H+gerLs4ltQ4RAkxMAKCYMC7HKTddmCgog+yip3GZd/AChgCgr0k8 APQ337C2zCxBQBOYIuWFKNU= =MVtV -----END PGP SIGNATURE----- _______________________________________________ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )