Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments with ORMapping
Shane Hathaway [EMAIL PROTECTED] said: That's one reason ZODB is so nice. You can write an application without writing a formal schema. One of the reasons I am seriously considering to migrate our production database from PostgreSQL to ZODB. I am about to implement our product database, and it is just too darn complex to bother maintaining SQL tables for it... Actually OracleStorage and bsddbstorage, recently released, are designed to address concerns about performance and reliability, and they do an excellent job at it. And I consider ZODB as real an OODB as anything else. (In some ways it's the best out there IMHO.) I heard that OracleStorage was quite a bit slower? And from what I've seen from FileStorage, it's a basic transaction log - what can be more reliable than that? Are people using ZODB for non-Zope data? I'd be very interested to discuss things like emulating extents, patterns for indexing, etcetera... ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Experiments with ORMapping
Shane Hathaway wrote: Kapil gave Jim and I a good introduction to SmartObjects yesterday. So far, it seems a lot like ZPatterns in that it mandates a new database access API rather than trying to be transparent like ZODB. The other is TransWarp, which has a slightly different focus, but Phillip Eby is also on our list, so we won't duplicate efforts. TransWarp doesn't try to be transparent either AFAICT... doing this transparently would be unbelievably cool :-) So, if I had a.n.other SQL table containing some attributes, how would you see that mappign to Zope objects? What meta_type would they be? Where would they show up? cheers, Chris ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Re: Grrr... Python Scripts
Chris McDonough wrote:
Here Chris, I'll try to solve your pain (untested):
from AccessControl import ModuleSecurityInfo
ModuleSecurityInfo('Products').declarePublic('Catalog')
ModuleSecurityInfo('Products.Catalog').declarePublic('CatalogError')
Could that we added to PythonScripts/standard.py so I don't have to do it all
the time?
Is it a patch worthy of the collector? ;-)
cheers,
Chris
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[Zope-dev] CoreSessionTracking 0.8 strangeness
Hi, We're developing a shopping cart using the CoreSessionTracking product v0.8, but we've run into a strange problem; once in a while getSessionData() will create a new session data object (the token value remains the same), and us that for a while. Now we'll end up having two different shopping cart objects, with getSessionData() randomly returning one of them them. We're running Zope 2.3.1. Could it be that some threads can't find the shared session data object and creates their own? The only thing changing between each HTTP request is the thread serving the request, AFAIK. Regards, -- Bjorn Stabell [EMAIL PROTECTED] ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Experiments with ORMapping
Hi! Do you know that there already is a project for OR-Mapping in Zope (actually there are two ...)? Yes, and I think the projects need to look into replacing parts of ZODB rather than adding complexity. ZODB has pieces that can be split apart and replaced as needed, such as caching, persistence, transactions, the pickle jar, the multi-threaded connection factory, and the storage layer. I'm hoping we can achieve OR mapping by only replacing the pickle jar, i.e. Connection.py. The current design plans of SmartObjects are mainly based on the assumption that we will not be able to change Zope itself. This is not a dogma for us, however. I guess doing OR-mapping in the Zope core would be fine with us ;-) But I am quite sure it will not solve ALL issues SmartObjects is going to tackle. One of the things we want to accomplish is better ZClasses. Another thing is queries: You enumerated a couple of reasons why people would use SQL instead of ZODB. One is integration of legacy data of course. But the more important one for us is that we still believe that even with ZCatalog Zope can not really do efficient croos-tree queries in all cases. A query like Give me all users who have bought this and that product and are aged 20 or above can not be handled by the catalog, I think. Same with the appointment things in our groupware project: While it is trivial for SQL to return me all appointments all members of my project have on a specific day (security is handled by the SmartObjects folders' methods in that case), ZODB/ZCatalog would only be able to resolve this question if either all appointments are stored in a central folder (what about security then?) or everything is cataloged (again, the standard ZCatalog does not handle security here, right?) What I need is an object-oriented storage (and I agree that ZODB is one of the best of them) that can efficiently be queried cross-tree. One different approach to this topic could be a better ZCatalog (maybe one that stores the catalog in relational tables). Ours is SmartObjects (http://demo.iuveno-net.de/iuveno/Products/SmartObjects). Also see the mailing list archive at http://imail.iuveno-net.de/pipermail/smartobjects/. Kapil gave Jim and I a good introduction to SmartObjects yesterday. So far, it seems a lot like ZPatterns in that it mandates a new database access API rather than trying to be transparent like ZODB. I think whether SmartObjects (in the current design) can be called transparent depends on the level. On the user level, they will be. You can Add them to folders, cutpaste them, upload them via FTP etc. The Zope security API is also used. So they are much more transparent than direct connections to LDAP, SQL, or to the file system (o.k. for the filesystem extFile does this already). Some of the API will definitely be needed: A SmartObject will have to be connected to databases like SQL-DAs or LDAPAdapter have to. So there has to be a ZMI-Plugin, and there has to be an API for that. SmartObjects is more of a programming framework than just adding OR-Mapping to Zope. So if we can solve the storage and query parts more efficiently by just having Zope itself extended a bit, this would be very cool ... Cheers, Joachim ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Experiments with ORMapping
So, if I had a.n.other SQL table containing some attributes, how would you see that mappign to Zope objects? What meta_type would they be? Where would they show up? That's why we need an API and can't just do everything transparently ;-) We have the conept of SmartAttributeSheets (names can change ;-)) that can be added to any object or class and map to certain SQL or LDAP sources. ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Experiments with ORMapping
But storage of binary pickles was never the intention anyway. I created a little interface that would allow you to store different classes in different PostgreSQL tables. Before I got to implementing anything, Is this much like the ZPatterns approach? Which part of ZPatterns are you referring to? The idea is to (generally) put all instances of a class in a certain table. But the implementation details having nothing in common with ZPatterns. That's the basic approach for SmartObjects, too. Or do we want to make some automatism to get tables created and destroyed according to ZClasses needs? SmartObjects would also do that. But not with the existing ZClasses. There will be something similar that you can use to define the schemas and that then creates the classes and the tables on the fly. I was thinking there would be a default table where everything gets stored by default. A programmer then tells the ORMapping about specific classes and how to store them. ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
[Zope-dev] Xron
Hi, I did install the xron product from Istaffor, but it doesn't work. I am using Zope - .2.3.2, and installed xron. But, when I want to access the zope - server, I get a zero response back. Does anyone no the answer to this problem ? Thanks, Els Homan __ ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
[Zope-dev] : XCRON
Hi, I did install the xron product from Istaffor, but it doesn't work. I am using Zope - .2.3.2, and installed xron. But, when I want to access the zope - server, I get a zero response back. Does anyone no the answer to this problem ? Thanks, Els Homan Ps. Log-file: -- 2001-05-11T09:55:30 INFO(0) ZServer HTTP server started at Fri May 11 11:55:30 2001 Hostname: localhost Port: 8080 -- 2001-05-11T09:55:30 INFO(0) ZServer FTP server started at Fri May 11 11:55:30 2001 Hostname: speedy Port: 8021 -- 2001-05-11T09:55:30 INFO(0) ZServer PCGI Server started at Fri May 11 11:55:30 2001 Unix socket: /usr/local/Zope-2.3.1-linux2-x86/var/pcgi.soc -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Hi, I just forked off a kid: 2548 -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Hi, I just forked off a kid: 2550 -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:50 INFO(0) Products.Xron.Loggerr Created new Schedule __ ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments with ORMapping
The other motivations for an RDBMS are (1) people have existing schemas and want Zope to access the same data as their existing apps, and they want it to be transparent, and (2) tables with millions of entries are easily stored in Zope but the perception is that the catalog isn't as fast as a database index. No one has done any tests AFAIK. Then we should do these tests. E.g. I'd like to see: - 20 GB of Word and PDF documents stored in the ZODB and full-text + metadata indexed in ZCatalog - the complete [EMAIL PROTECTED] mailing list archive in the ZODB If Zope can handle those without the help of external tools (RDBMS etc.), I'll use it for all our Document Management ... That's one reason ZODB is so nice. You can write an application without writing a formal schema. Another thing (from the Slashdot article earlier this week): In Java, changes to the object structure mean recompile. In Zope, you can just do them. with working refresh support this will even work without having to restart the Zope process ... What about using a real oodb for zope? Dont remember any particular product name, but I heard something. Actually OracleStorage and bsddbstorage, recently released, are designed to address concerns about performance and reliability, and they do an excellent job at it. And I consider ZODB as real an OODB as anything else. (In some ways it's the best out there IMHO.) Agreed. ZODB has a much longer proven history of success than most other OODBs. ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] CoreSessionTracking 0.8 strangeness
This is very odd, as cst depends on ZODB locking just like everything else in Zope, and uses the same transaction facilities and semantics. Now this may *be* the problem... some other folks have explained a problem where newly-created session data disappears if the long-running request that created it is aborted... this may make sense, because the request never gets the chance to finish, and the session data object never gets committed to the database because the ZODB transaction is aborted. It may be the case (especially if you're using frames or multiple windows) that simultaneous concurrent initial requests for a session data object from the same client might cause one of two newly-created data objects to be lost. But I can't imagine a case where a session data object exists for a while (a few minutes), and then a client comes in with the same sessionid, and a new session data object is created for him, not *replacing* the old one, but in addition to the old one... the only possibility for something like this that I can see is on initial request, or if a particularly long-running method creates a session data object, and a user comes in directly after it... ah, wait. I think I see how this can happen. 1. User hits /longrunningmethod. 2. /longrunningmethod creates a session data object as part of its operation. 3. /longrunning method requires 1 minute to process completely. 4. In the meantime, the user (in a separate window or frame) visits /shortrunningmethod. 5. /shortrunningmethod creates a session data object as part of its operation. 6. /shortrunningmethod completes and the session data object it created is committed to the ZODB. 7. User visits /shortrunningmethod2, which modifies the existing session data object, /shortunningmethod3, which also does this, etc. 8. In the meantime, /longrunningmethod finishes and replaces the session data object which has stuff in it from the shortrunningmethods with the one it created. I'm not completely 100% sure about this, but at least it's something to test. Could this be what's happening to you? I may have been overzealous when dealing with confict error problems here... basically, the conflict error detection stuff is disabled for session data objects, which makes this sort of thing possible and likely. Conflict error detection is the ZODB equivalent of record-locking... and when it's ignored, you can have some of the same problems that happen in a nontransactional system (like the problem I outlined above). Sigh. - C Bjorn Stabell wrote: Hi, We're developing a shopping cart using the CoreSessionTracking product v0.8, but we've run into a strange problem; once in a while getSessionData() will create a new session data object (the token value remains the same), and us that for a while. Now we'll end up having two different shopping cart objects, with getSessionData() randomly returning one of them them. We're running Zope 2.3.1. Could it be that some threads can't find the shared session data object and creates their own? The only thing changing between each HTTP request is the thread serving the request, AFAIK. Regards, -- Bjorn Stabell [EMAIL PROTECTED] ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope ) ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Re: Grrr... Python Scripts
We actually need to do something to make a whole bunch of default stuff
importable and usable from within Python Scripts, it's just a matter of
which modules/classes to add security declarations for. It's also a
matter of when, and who. This needs to go through the fishbowl,
likely. Now if only we could manufacture some more time...
- C
Chris Withers wrote:
Chris McDonough wrote:
Here Chris, I'll try to solve your pain (untested):
from AccessControl import ModuleSecurityInfo
ModuleSecurityInfo('Products').declarePublic('Catalog')
ModuleSecurityInfo('Products.Catalog').declarePublic('CatalogError')
Could that we added to PythonScripts/standard.py so I don't have to do it all
the time?
Is it a patch worthy of the collector? ;-)
cheers,
Chris
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Re: [Zope-dev] New IOBTrees have no 'map' method
Chris Withers wrote: R. David Murray wrote: My guess, after searching for the keyword 'map' and finding an interface that calls for the implementation of __getitem__ and says this allows 'for' loops and 'map' iterations, is that you can just drop the call to the .map method and use the IOBtree directly as the argument to the map function. But in the absence of real knowledge about what the .map method of the old IOBTree does, that is just a guess. Well, to give you an idea of what it did, here's the method I had to write toreplace the functionality: def data_map(self,ids): result=[] for id in ids: result.append(self.data[id].__of__(self)) return result self.data is an IOBTree. If this can be replaced wiith a simple return map(...,self.data), please let me know :-) Untested... return map(lambda x, data=self.data, self=self: data[x].__of__(self), ids) ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] New IOBTrees have no 'map' method
Chris McDonough wrote: Untested... return map(lambda x, data=self.data, self=self: data[x].__of__(self), ids) ah, I see :-) Would that be faster than my little function? cheers, Chris ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Re: Grrr... Python Scripts
Chris McDonough wrote: We actually need to do something to make a whole bunch of default stuff importable and usable from within Python Scripts, it's just a matter of which modules/classes to add security declarations for. Maybe this could be bundled into the RestrictedPython work? It's also a matter of when, and who. This needs to go through the fishbowl, likely. Now if only we could manufacture some more time... There's a feeling I know too well :-S cheers, Chris ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] New IOBTrees have no 'map' method
Chris Withers wrote: Chris McDonough wrote: Untested... return map(lambda x, data=self.data, self=self: data[x].__of__(self), ids) ah, I see :-) Would that be faster than my little function? Probably not appreciably... unless it is, of course. ;-) It depends how many things you're iterating over. Might even be slower... it'd require testing and its probably not worth it. - C ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] : XCRON
Hi, I have installed it as well and can neither get it to work. It does nearly what it is supposed to by scheduling the scripts to execute, but the final execution does never occur. ANy tricks out there are good news for me as well, Espen On Fri, 11 May 2001, Homan Els wrote: Hi, I did install the xron product from Istaffor, but it doesn't work. I am using Zope - .2.3.2, and installed xron. But, when I want to access the zope - server, I get a zero response back. Does anyone no the answer to this problem ? Thanks, Els Homan Ps. Log-file: -- 2001-05-11T09:55:30 INFO(0) ZServer HTTP server started at Fri May 11 11:55:30 2001 Hostname: localhost Port: 8080 -- 2001-05-11T09:55:30 INFO(0) ZServer FTP server started at Fri May 11 11:55:30 2001 Hostname: speedy Port: 8021 -- 2001-05-11T09:55:30 INFO(0) ZServer PCGI Server started at Fri May 11 11:55:30 2001 Unix socket: /usr/local/Zope-2.3.1-linux2-x86/var/pcgi.soc -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Hi, I just forked off a kid: 2548 -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Hi, I just forked off a kid: 2550 -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:50 INFO(0) Products.Xron.Loggerr Created new Schedule __ ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope ) ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] New IOBTrees have no 'map' method
Chris McDonough wrote: Probably not appreciably... unless it is, of course. ;-) It depends how many things you're iterating over. self.data can often contain several thousand objects. Might even be slower... it'd require testing and its probably not worth it. Hehe, I'll leave it then, unless someone complains abotu Squishdot being dog slow... cheers, Chris ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Re: Grrr... Python Scripts
Chris Withers wrote: Maybe this could be bundled into the RestrictedPython work? I think it needs to be its own project... the RestrictedPython work is being done at a much lower level than this. ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Re: Grrr... Python Scripts
From: Chris Withers [EMAIL PROTECTED] Could that we added to PythonScripts/standard.py so I don't have to do it all the time? This is just part of a general security review that needs to happen. I suppose we need a place to collect suggestions about objects that ought to be exposed to restricted Python. Cheers, Evan @ digicool ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Experiments with ORMapping
Joachim Werner wrote: Hi! Do you know that there already is a project for OR-Mapping in Zope (actually there are two ...)? Yes, and I think the projects need to look into replacing parts of ZODB rather than adding complexity. ZODB has pieces that can be split apart and replaced as needed, such as caching, persistence, transactions, the pickle jar, the multi-threaded connection factory, and the storage layer. I'm hoping we can achieve OR mapping by only replacing the pickle jar, i.e. Connection.py. The current design plans of SmartObjects are mainly based on the assumption that we will not be able to change Zope itself. This is not a dogma for us, however. I guess doing OR-mapping in the Zope core would be fine with us ;-) FYI by replacing I don't mean changing anything in the Zope core. I mean using a different class in place of Connection, which you can do just by creating a custom_zodb.py. But I am quite sure it will not solve ALL issues SmartObjects is going to tackle. One of the things we want to accomplish is better ZClasses. Another thing is queries: You enumerated a couple of reasons why people would use SQL instead of ZODB. One is integration of legacy data of course. It sounds like you are tackling a lot of things at once. You might consider dividing into separate projects. But the more important one for us is that we still believe that even with ZCatalog Zope can not really do efficient croos-tree queries in all cases. A query like Give me all users who have bought this and that product and are aged 20 or above can not be handled by the catalog, I think. Yes it can. :-) That's not to say that it has as much flexibility as a SQL query, but it can do most of the things people usually do with one table at a time. Here's the goal I envision for OR mapping: to be able to move between OODBMS and RDBMS seamlessly. It makes sense to develop on top of ZODB then move to an RDBMS for testing and deployment. Same with the appointment things in our groupware project: While it is trivial for SQL to return me all appointments all members of my project have on a specific day (security is handled by the SmartObjects folders' methods in that case), ZODB/ZCatalog would only be able to resolve this question if either all appointments are stored in a central folder (what about security then?) or everything is cataloged (again, the standard ZCatalog does not handle security here, right?) The CMF has a solution for this, actually. The results of a query include only the things you're allowed to access. What I need is an object-oriented storage (and I agree that ZODB is one of the best of them) that can efficiently be queried cross-tree. One different approach to this topic could be a better ZCatalog (maybe one that stores the catalog in relational tables). Right. I agree an *alternate* ZCatalog would be useful. Ours is SmartObjects (http://demo.iuveno-net.de/iuveno/Products/SmartObjects). Also see the mailing list archive at http://imail.iuveno-net.de/pipermail/smartobjects/. Kapil gave Jim and I a good introduction to SmartObjects yesterday. So far, it seems a lot like ZPatterns in that it mandates a new database access API rather than trying to be transparent like ZODB. I think whether SmartObjects (in the current design) can be called transparent depends on the level. On the user level, they will be. You can Add them to folders, cutpaste them, upload them via FTP etc. The Zope security API is also used. So they are much more transparent than direct connections to LDAP, SQL, or to the file system (o.k. for the filesystem extFile does this already). Some of the API will definitely be needed: A SmartObject will have to be connected to databases like SQL-DAs or LDAPAdapter have to. So there has to be a ZMI-Plugin, and there has to be an API for that. SmartObjects is more of a programming framework than just adding OR-Mapping to Zope. So if we can solve the storage and query parts more efficiently by just having Zope itself extended a bit, this would be very cool ... You see, I think it is not necessary to create a programming framework if the goal is OR mapping. The framework is already defined, and it's Python / ZODB. But SmartObjects seems to have many loosely related goals, making it difficult to assist. Shane ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments withORMapping
On friday, 11 May, Joachim Warner wrote: The other motivations for an RDBMS are (1) people have existing schemas and want Zope to access the same data as their existing apps, and they want it to be transparent, and (2) tables with millions of entries are easily stored in Zope but the perception is that the catalog isn't as fast as a database index. No one has done any tests AFAIK. Then we should do these tests. E.g. I'd like to see: - 20 GB of Word and PDF documents stored in the ZODB and full-text + metadata indexed in ZCatalog - the complete [EMAIL PROTECTED] mailing list archive in the ZODB If Zope can handle those without the help of external tools (RDBMS etc.), I'll use it for all our Document Management ... As a matter of fact, we did a quick CMF demo that has the content of the zope list, zope-dev, and many of the other zope.org lists, and the comp.lang.python list for the past few years. The catalog searches are very very fast, i can't recall if the demo was set up with some interesting canned CMF topics, but the things works well. The picture isn't altogether rosy - the process of loading the objects was arduous. On the other hand, the exercise (actually, a subsequent one with simpler article objects) served as the basis for tuning the cataloging process, and may have helped it get a lot better. If i have time next week, i'll see if we have the corpus online somewhere. (The lists were complete up to a few months ago.) Eventually we'd like to be incrementally stuffing new messages into the database as they arrive. The catalog has required some substantial work investment, but from my viewpoint (particularly since i haven't had to work on it!-), it's well worth it. Actually OracleStorage and bsddbstorage, recently released, are designed to address concerns about performance and reliability, and they do an excellent job at it. And I consider ZODB as real an OODB as anything else. (In some ways it's the best out there IMHO.) Agreed. ZODB has a much longer proven history of success than most other OODBs. It is quite useful! I have no experience programming with other object databases, and very little with relational databases, so i have no basis for comparison. What i do know, as a python and zope programmer, is that ZODB is spectacularly useful as a persistent store - as flexible *and* as powerful as i could want. The addition of ZEO manages to significantly increase that usefulness! The work we/pythonlabs (and andrew kuchling, etc) is doing to enable use of it as an independent entity can only help improve it's usefulness for everyone. Ken Manheimer [EMAIL PROTECTED] ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
RE: Subject: [Zope-dev] change ownership
Magnus, OK, here goes the evil workaround It seems that getUser does not return an acquisition wrapped object, so make your external method this to wrap it (thus giving ownerinfo the ability to determine the user db): def setOwner(self, username): #note: this assumes that the closest User database houses 'username' user = self.acl_users.getUser(username) self.changeOwnership(user.__of__(self.acl_users)) return 'done.' --Tim McLaughlin (tmclaugh) -Original Message- From: Magnus Heino (Rivermen) To: 'Tim McLaughlin'; Magnus Heino (Rivermen) Sent: 5/11/01 1:20 AM Subject: SV: Subject: [Zope-dev] change ownership could you give me a url, name pw, and let me take a look at the zclass? Nope, I'm doing this on my laptop behind a firewall. But, this is how to reproduce it; This is my external method: [magnus@daysleeper Extensions]$ cat Owner.py def setObjectOwner(self, username): self.changeOwnership(self.acl_users.getUser(username)) return '%s is now the owner of %s' % (username, self.id) def getObjectOwner(self): return self.getOwner() [magnus@daysleeper Extensions]$ Goto Control_Panel/Products. Add a product 'FooProduct'. Enter the FooProduct and create a ZClass with id and metatype 'FooClass'. Enter the FooClass and add a External Method. Set Id and Function Name to 'setObjectOwner'. Module name is 'Owner'. Go to the Root zope folder. It contains a standard acl_users. Add a FooClass named 'foo'. Call the external method on the object like this: http://192.168.237.105:8080/foo/setObjectOwner?username=magnus magnus is my username that lives in the acl_users. You get the Attributeerror on aq_inner. Any clues? :-P Thanks. /Magnus ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
RE: [Zope-dev] Xron
This is a known problem. Search back thru the archives of [EMAIL PROTECTED] for Xron and you will find some helpful information. I'll also try to find the relevant email and forward it to you separately. -- Loren (lstaffor) -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Homan Els Sent: Friday, May 11, 2001 06:23 To: [EMAIL PROTECTED] Subject: [Zope-dev] Xron Hi, I did install the xron product from Istaffor, but it doesn't work. I am using Zope - .2.3.2, and installed xron. But, when I want to access the zope - server, I get a zero response back. Does anyone no the answer to this problem ? Thanks, Els Homan __ ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope ) ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] New IOBTrees have no 'map' method
On Fri, 11 May 2001, Chris Withers wrote: Probably not appreciably... unless it is, of course. ;-) It depends how many things you're iterating over. Hehe, I'll leave it then, unless someone complains abotu Squishdot being dog slow... If you haven't already read it, you might be interested in this article: http://www.python.org/doc/essays/list2str.html --RDM ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments with ORMapping
Cees de Groot wrote: Shane Hathaway [EMAIL PROTECTED] said: That's one reason ZODB is so nice. You can write an application without writing a formal schema. One of the reasons I am seriously considering to migrate our production database from PostgreSQL to ZODB. I am about to implement our product database, and it is just too darn complex to bother maintaining SQL tables for it... Actually OracleStorage and bsddbstorage, recently released, are designed to address concerns about performance and reliability, and they do an excellent job at it. And I consider ZODB as real an OODB as anything else. (In some ways it's the best out there IMHO.) I heard that OracleStorage was quite a bit slower? And from what I've seen from FileStorage, it's a basic transaction log - what can be more reliable than that? Are people using ZODB for non-Zope data? I'd be very interested to discuss things like emulating extents, patterns for indexing, etcetera... One of the biggest limitations in my mind is the lack of a general query language for the ZODB like what you get with most OODBMS and all RDBMS. ZCatalog is improving, but it is just not quite there yet. I do feel that the ZODB is quite robust, and with the added option of berkeley storage along with others, you have several back-end choices. -- | Casey Duncan | Kaivo, Inc. | [EMAIL PROTECTED] `-- ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments with ORMapping
At 11:45 AM 5/11/2001 -0600, Casey Duncan wrote: One of the biggest limitations in my mind is the lack of a general query language for the ZODB like what you get with most OODBMS and all RDBMS. I used to think this as well. But isn't Python a decent query language? Isn't it nice to be able to have all of the facilities of Python at your disposal when manipulating data, rather than hoping that whatever database you are using doesn't have a brain-damaged implementation of SQL? Isn't it nice not to have to convert back and forth between SQL types and native types? Isn't it nice not to have to swap in your SQL mind in the middle of your Python program? Having a general query language makes it easy for people who know that particular general query language to write programs. It makes it easy to access a bunch of different data sources, at least until the monster named implementation differences rears it's ugly head. We've all spent years learning to make our programs interface with databases, learning how to jump the mental chasm between our programs and they way they want to manipulate data, and the way that the database wants to manipulate data. Isn't it nice not to have to do that any more? Don't get me wrong, I believe I get your point. SQL implementations are getting more and more compatible. There are OODBMS query languages specified. There's no really good way of making different programming languages and programming environments interoperate without some sort of common meeting ground, like a general query language. And perhaps I'm overdoing the response, perhaps I've gone off in a different direction. I've just been thinking about this quite a bit lately. dave ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments withORMapping
As a matter of fact, we did a quick CMF demo that has the content of the zope list, zope-dev, and many of the other zope.org lists, and the comp.lang.python list for the past few years. The catalog searches are very very fast, i can't recall if the demo was set up with some interesting canned CMF topics, but the things works well. Sounds very promising ... The picture isn't altogether rosy - the process of loading the objects was arduous. What exactly were the problems? I mean, uploading and indexing thousands of documents IS a big deal. I'm sure that any other indexing system will take a lot of time for this, too. Joachim ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments with ORMapping
But isn't Python a decent query language? Isn't it nice to be able to have all of the facilities of Python at your disposal when manipulating data, rather than hoping that whatever database you are using doesn't have a brain-damaged implementation of SQL? Most of the time nobody will need SQL. And having a transparent, transaction-aware and undoable persistent Object store is really a cool thing. But from time to time you will hit walls. That's when the object paradigm just does not do the job completely well any more. E.g. how would you handle objects beloning to more than one container? In SQL this is easy (Just have a table that matches key pairs from the container table and the item table). And I don't know any good way of implementing many-to-many relations in object hierarchies. Let alone querying them efficiently. Joachim ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
RE: [Zope-dev] : XCRON
1. Be sure to use the STUPID_LOG_FILE or run Zope in debug mode. That's the only way you will know what Xron's Dispatcher is doing. 2. Xron DTML Methods run as Anonymous User. You may have to give your Xron DTML Methods proxy roles so that they can execute the functions you want them to. This is a common problem for Xron DTML Methods that send email. They have to have permission to use mailhost services. 3. Beware of the Catalog bug in 2.3.1bx. 4. Search the archives of [EMAIL PROTECTED] for Xron. You will find helpful information about issues that other users have already discovered. -- Loren -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Espen Sorbye Frederiksen Sent: Friday, May 11, 2001 06:35 To: Homan Els Cc: [EMAIL PROTECTED] Subject: Re: [Zope-dev] : XCRON Hi, I have installed it as well and can neither get it to work. It does nearly what it is supposed to by scheduling the scripts to execute, but the final execution does never occur. ANy tricks out there are good news for me as well, Espen On Fri, 11 May 2001, Homan Els wrote: Hi, I did install the xron product from Istaffor, but it doesn't work. I am using Zope - .2.3.2, and installed xron. But, when I want to access the zope - server, I get a zero response back. Does anyone no the answer to this problem ? Thanks, Els Homan Ps. Log-file: -- 2001-05-11T09:55:30 INFO(0) ZServer HTTP server started at Fri May 11 11:55:30 2001 Hostname: localhost Port: 8080 -- 2001-05-11T09:55:30 INFO(0) ZServer FTP server started at Fri May 11 11:55:30 2001 Hostname: speedy Port: 8021 -- 2001-05-11T09:55:30 INFO(0) ZServer PCGI Server started at Fri May 11 11:55:30 2001 Unix socket: /usr/local/Zope-2.3.1-linux2-x86/var/pcgi.soc -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Hi, I just forked off a kid: 2548 -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Hi, I just forked off a kid: 2550 -- 2001-05-11T10:12:44 INFO(0) zdaemon zdaemon: Fri May 11 12:12:44 2001: Houston, we have forked -- 2001-05-11T10:12:50 INFO(0) Products.Xron.Loggerr Created new Schedule __ ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope ) ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope ) ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Experiments with ORMapping
It sounds like you are tackling a lot of things at once. You might consider dividing into separate projects. Yep, that's what is happening right now. We are still collecting feature requests. Then we will sort them out. A lot of the stuff will also be useful in different contexts than we have planned, so maybe these things should be in a different project ... I'm sure about one thing: SmartObjects will be the wron name for most of the things we are tackling ... A query like Give me all users who have bought this and that product and are aged 20 or above can not be handled by the catalog, I think. Yes it can. :-) That's not to say that it has as much flexibility as a SQL query, but it can do most of the things people usually do with one table at a time. I am talking about MANY tables (or object relations) ... ;-) In the example, it's users in many different sub-folders (e.g. branded portals), products from a product catalog, etc. If you KNOW in advance that you will need the info, you can easily store the info pairs in the Catalog, but if you just want to do ad-hoc data mining ... The CMF has a solution for this, actually. The results of a query include only the things you're allowed to access. That's why I said standard ;-) SmartObjects is more of a programming framework than just adding OR-Mapping to Zope. So if we can solve the storage and query parts more efficiently by just having Zope itself extended a bit, this would be very cool ... You see, I think it is not necessary to create a programming framework if the goal is OR mapping. The framework is already defined, and it's Python / ZODB. But SmartObjects seems to have many loosely related goals, making it difficult to assist. But Python/ZODB is not a high-level framework. Like Zope is not the CMF. Nobody would implement GUIs in pure C now. They are using tools for that. And we don't want to have to implement things like HTML forms, event handling, etc. over and over again. We want to just configure and compile. Of course this will be within the Python/ZODB framework, i.e. all the additional functionality will be support classes or mix-in classes like the ones Zope already offers (e.g. CatalogAware). ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments withORMapping
David Brown wrote: At 11:45 AM 5/11/2001 -0600, Casey Duncan wrote: One of the biggest limitations in my mind is the lack of a general query language for the ZODB like what you get with most OODBMS and all RDBMS. I used to think this as well. But isn't Python a decent query language? Isn't it nice to be able to have all of the facilities of Python at your disposal when manipulating data, rather than hoping that whatever database you are using doesn't have a brain-damaged implementation of SQL? No and yes. Python is a great oop language, it has no inherent querying capabilites though outside of namespace lookups (with acquisition when in Zope) and dictionaries. You would need to build in all possible queries as Python methods none of which would be very general. This is something you need not do with a general query language where you can make arbitrary queries at will. Isn't it nice not to have to convert back and forth between SQL types and native types? Isn't it nice not to have to swap in your SQL mind in the middle of your Python program? I am not arguing necessarily for SQL as a query language for the ZODB. Although it is an accepted standard, but not a perfect one by any means especially for OODBs. Its appeal lies mainly in the high level of community familiarity and the plethora of SQL software to borrow from. Having a general query language makes it easy for people who know that particular general query language to write programs. It makes it easy to access a bunch of different data sources, at least until the monster named implementation differences rears it's ugly head. We've all spent years learning to make our programs interface with databases, learning how to jump the mental chasm between our programs and they way they want to manipulate data, and the way that the database wants to manipulate data. Isn't it nice not to have to do that any more? Yes, I would argue for a tight integration between the query mechanism and regular Python, something that Catalogs have begun to implement. However their query language is a very limiting argument list. Perhaps a more general Python based query language of some kind needs to be developed. Something like an expression that returns the set of objects that meet its criteria. Exactly what this would be would need much community (Python and Zope) discussion. A start to this discussion can be found here: http://dev.zope.org/Wikis/DevSite/Proposals/UnionAndIntersectionOperations Don't get me wrong, I believe I get your point. SQL implementations are getting more and more compatible. There are OODBMS query languages specified. There's no really good way of making different programming languages and programming environments interoperate without some sort of common meeting ground, like a general query language. A be all query language for all databases (Which would be SQL at this point, which is not necessarily tailored to OODBs) will always have compromises and flaws. I look at something like CORBA which is can be used to tie programs of all different languages together. Unfortunately the result of reconsiling COBOL, C, Python, Java, Perl, BASIC, etc. to some common ground is not always very pretty. I would really be happy just to get Python (and possibly C) to be able to perform general ZODB queries without resorting to kludges like spam_usage='range:min:max'. So what I am talking about is not really general, but mostly Python/ZODB specific. And perhaps I'm overdoing the response, perhaps I've gone off in a different direction. I've just been thinking about this quite a bit lately. dave I think this is a very important topic of discussion. Thanks for adding your thoughts! -- | Casey Duncan | Kaivo, Inc. | [EMAIL PROTECTED] `-- ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments with ORMapping
At 08:38 PM 5/11/2001 +0200, you wrote: E.g. how would you handle objects beloning to more than one container? In SQL this is easy (Just have a table that matches key pairs from the container table and the item table). I could do the same thing with Python, creating a dictionary that does the mapping. You'd have to maintain the dictionary, sure, but you'd have to maintain the table in a relational database as well. And I don't know any good way of implementing many-to-many relations in object hierarchies. Let alone querying them efficiently. Well, then we need a many-to-many mapping object. The point is that we could do this in Python and make the classes available, rather than morphing our thought processes into whatever shape the RDBMS wants. We're just missing some functionality, but it can be written without rewriting the database code, because we can just store our objects (representing indices or mappings or whatever) directly. The cool thing about object stores is that you can use the object modeling tools to do the job, and come up with specific (and more efficient) solutions, rather than mapping a general (and possibly slower) solution onto a specific problem. dave ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments with
Cees de Groot wrote: David Brown [EMAIL PROTECTED] said: But isn't Python a decent query language? Isn't it nice to be able to have all of the facilities of Python at your disposal when manipulating data, rather than hoping that whatever database you are using doesn't have a brain-damaged implementation of SQL? Yup. Our business objects are sitting on top of my homebrew O/R mapping layer, and I find myself entering the Python shell to do ad-hoc stuff with them more and more often. Especially because stuff that repeats one or two times is easily added as a method on the object for later reference... One nice idea that should be possible in Pythonland as well: a Smalltalk O/R mapping layer called GLORP uses Smalltalk as a query language in a very nice way. Queries are given as Smalltalk blocks (say lambdas), and the mapping layer interprets the block's parse tree in order to spit out equivalent SQL code. Say: Employees.get(lambda e: e.name[:3] == 'Foo') to get all employees that have a name starting with Foo. The only problem with this is that lambdas are not safe for TTW scripting 8^(. Although a safe lambda could probably be conceived of course... -- | Casey Duncan | Kaivo, Inc. | [EMAIL PROTECTED] `-- ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Question about import code
Shane Hathaway writes: Fred Wilson Horch wrote: Importing multiple objects simultaneously could result in a fair amount of confusion... Can you elaborate? When you import a folder, for example, it imports the folder and all objects in it. If there are some objects in the folder that have conflicting names and others that don't, what do you do? Zope already solves this problem for paste. Although, I am not sure that I like this solution, import should behave the same, for consistency. Also, if you're thinking about providing this functionality, what about spanning multiple folders? What if some folders already exist? Again, it should behave like paste, for consistency. Dieter ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments with
[EMAIL PROTECTED] said: The only problem with this is that lambdas are not safe for TTW scripting 8^(. I think that TTW scripting and heavy duty application development are very incompatible with each other, so that's not a problem :-) -- Cees de Groot http://www.cdegroot.com [EMAIL PROTECTED] GnuPG 1024D/E0989E8B 0016 F679 F38D 5946 4ECD 1986 F303 937F E098 9E8B ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Experiments with ORMapping
At 11:01 AM 5/11/01 -0400, Shane Hathaway wrote: Joachim Werner wrote: The current design plans of SmartObjects are mainly based on the assumption that we will not be able to change Zope itself. This is not a dogma for us, however. I guess doing OR-mapping in the Zope core would be fine with us ;-) FYI by replacing I don't mean changing anything in the Zope core. I mean using a different class in place of Connection, which you can do just by creating a custom_zodb.py. Hm. So you're suggesting creation of a Storage class that returns a special root object which emulates the standard ZODB root PersistentMapping, and contains another object that emulates a folder, with a bunch of other foldoids that are actually tables, or something of that sort? And maybe exposes some query methods ala ZCatalog? I'm not quite clear on how exactly you suggest mapping from RDMBS - ZODB. There's a *significant* (IMHO) impedance mismatch between ZODB's arbitrarily identified variably structured single records and SQL's content-identified fixed-structure record sets. This is what application frameworks/toolkits (such as your own DBAPI product) are needed for. But the more important one for us is that we still believe that even with ZCatalog Zope can not really do efficient croos-tree queries in all cases. A query like Give me all users who have bought this and that product and are aged 20 or above can not be handled by the catalog, I think. Yes it can. :-) That's not to say that it has as much flexibility as a SQL query, but it can do most of the things people usually do with one table at a time. Here's the goal I envision for OR mapping: to be able to move between OODBMS and RDBMS seamlessly. It makes sense to develop on top of ZODB then move to an RDBMS for testing and deployment. Unfortunately, I think that this requirement can *only* be met through a common API or access pattern/framework/what-have-you, be it DBAPI, ZPatterns, SmartObjects, or TransWarp. The ZODB is both too powerful (in its flexibility) and too weak (in lack of any ZODB-level notions of record sets, schemas, and indexing) to be useful as a cross-database-platform API. That's not to denigrate any of the value of ZODB itself - an explicit goal of both ZP and TW is to leverage ZODB's flexibility in combination with other kinds of databases. (And, recently, I have been speculatively eyeing the ZODB for some mortgage-industry related projects which involve complex variable data structures, distribution requirements ala ZEO, and local data stores on intermittently-connected laptops.) SmartObjects is more of a programming framework than just adding OR-Mapping to Zope. So if we can solve the storage and query parts more efficiently by just having Zope itself extended a bit, this would be very cool ... You see, I think it is not necessary to create a programming framework if the goal is OR mapping. The framework is already defined, and it's Python / ZODB. But SmartObjects seems to have many loosely related goals, making it difficult to assist. I think the goal for SO, and all the other frameworks that have been created or are being created, is to *make application development easier*. OR mapping is just a means to that end. LDAP connectivity, or other types of non-ZODB data access are important to many of us, as well. This boils down to abstraction of how data attributes are represented. For example, if I am an ISP, and I want to implement an active flag on an account object, I would like changing it to automatically go out and add or remove routing entries and password entries on my servers when I update the record through my Zope interface (web, SOAP, or whatever). Could you make a ZODB Storage object that supported this? Maybe. But from an architectural standpoint it would be rather messy - akin to writing OO code with giant switch statements. The Java (and CORBA, actually) solution to this, is to use a property pattern, where a property is a non-real thing that actually only has setters and getters. An object's users always go through these accessor methods, so the implementation can be anything you like. (Notice, btw, how the solution is once again a framework pattern...) ZPatterns was an effort to produce a Pythonic emulation of this concept that didn't need actual methods. It unfortunately inherits some of the flaws of __getattr__ hooks, such as forced semi-centralization of implementations. TransWarp does away with that and instead introduces property (feature) objects which themselves have methods, but are not data. This provides a bit more extensibility than the Java approach, since it is conceivable one could add an observable interface to a property object and thus subscribe to it, for example. Anyway, all I'm really trying to say is, if you want implementation independence, you have to have implementation hiding. ZODB makes it easy to store
Re: [Zope-dev] Experiments with ORMapping
Phillip J. Eby wrote: At 11:01 AM 5/11/01 -0400, Shane Hathaway wrote: Joachim Werner wrote: The current design plans of SmartObjects are mainly based on the assumption that we will not be able to change Zope itself. This is not a dogma for us, however. I guess doing OR-mapping in the Zope core would be fine with us ;-) FYI by replacing I don't mean changing anything in the Zope core. I mean using a different class in place of Connection, which you can do just by creating a custom_zodb.py. Hm. So you're suggesting creation of a Storage class that returns a special root object which emulates the standard ZODB root PersistentMapping, and contains another object that emulates a folder, with a bunch of other foldoids that are actually tables, or something of that sort? And maybe exposes some query methods ala ZCatalog? No. The suggestion was to return something that implements the DB interface but doesn't use Connection.py to do it. I'm not quite clear on how exactly you suggest mapping from RDMBS - ZODB. There's a *significant* (IMHO) impedance mismatch between ZODB's arbitrarily identified variably structured single records and SQL's content-identified fixed-structure record sets. This is what application frameworks/toolkits (such as your own DBAPI product) are needed for. If you implement this at the Storage level, yes, there is a major mismatch. But at the Connection level it makes a lot of sense. Connection basically exposes a pile of pickles as objects; an OR mapping exposes a complex schema as objects. I think that understanding will change the rest of your response. :-) Shane ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments with ORMapping
Joachim Werner [EMAIL PROTECTED] said: [...]. E.g. how would you handle objects beloning to more than one container? In SQL this is easy (Just have a table that matches key pairs from the container table and the item table). And I don't know any good way of implementing many-to-many relations in object hierarchies. Let alone querying them efficiently. Probably I'm daft because it is Friday night, but AFAIK ZODB and most OODB's store an object only once, keyed by its object id. The rest is just references through that oid, so objects that belong to more than one container can be added to all these containers and n:m relations are implemented by having a list of objects on both sides. ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
