From: Edmund L. <el...@in...> - 2003-02-28 15:38:09
|
I have a question... please don't get offended by it, I don't mean it to be offensive... While I'm not a great fan of object oriented DBs, I do see a role for them in providing persistence when the demands of an application are lightweight (and don't require all the good stuff that relational DBs offer). I was reading one of Kuchling's write-ups about ZODB and ZEO last night (http://www.amk.ca/zodb/zodb-zeo.html), and was wondering why people use MiddleKit instead of ZODB. Why bother trying to persist to a relational DB if you can't really get at the full power of the relational model through MiddleKit (or any other ORM for that matter)? ZODB seems to be rather easy to use, and offers a whole bunch of things that MiddleKit doesn't implement (e.g., transactions, versioning, etc.) ZEO seems to be a neat way to spread work across several Webware instances (so long as the application is read intensive ) There hasn't been much discussion of using/integrating ZODB/ZEO into Webware as a standard persistence tool. Am I missing something? ...Edmund. |
From: Nick M. <ni...@go...> - 2003-02-28 15:57:28
|
Edmund Lian wrote: > Why bother trying to persist to a relational DB if you can't really get at > the full power of the relational model through MiddleKit (or any other ORM The most obvious reason would be for compatibility with an existing application sharing the same database... |
From: Jim B. <jb...@cn...> - 2003-02-28 15:58:59
|
I have never used an OODB, so I might be wrong, but I have always seen their weakness to be flexibility. You will get stuck with the objects you use for a particular application. With a relational DB you can map the data to any type of object. It is a little more complex because of the extra mapping step, but also more flexible IMHO. So there is a trade off of complexity vs flexibility. Edmund Lian wrote: > I have a question... please don't get offended by it, I don't mean it to be > offensive... > > While I'm not a great fan of object oriented DBs, I do see a role for them > in providing persistence when the demands of an application are lightweight > (and don't require all the good stuff that relational DBs offer). I was > reading one of Kuchling's write-ups about ZODB and ZEO last night > (http://www.amk.ca/zodb/zodb-zeo.html), and was wondering why people use > MiddleKit instead of ZODB. > > Why bother trying to persist to a relational DB if you can't really get at > the full power of the relational model through MiddleKit (or any other ORM > for that matter)? ZODB seems to be rather easy to use, and offers a whole > bunch of things that MiddleKit doesn't implement (e.g., transactions, > versioning, etc.) ZEO seems to be a neat way to spread work across several > Webware instances (so long as the application is read intensive ) > > There hasn't been much discussion of using/integrating ZODB/ZEO into > Webware as a standard persistence tool. Am I missing something? > > ...Edmund. > > > > ------------------------------------------------------- > This sf.net email is sponsored by:ThinkGeek > Welcome to geek heaven. > http://thinkgeek.com/sf > _______________________________________________ > Webware-discuss mailing list > Web...@li... > https://lists.sourceforge.net/lists/listinfo/webware-discuss > > |
From: Stephan D. <ste...@gm...> - 2003-02-28 16:26:01
|
On Friday 28 February 2003 16:37, you wrote: > I have a question... please don't get offended by it, I don't mean it to be > offensive... > > [...] > > There hasn't been much discussion of using/integrating ZODB/ZEO into > Webware as a standard persistence tool. Am I missing something? Probably not :-) I think the reason for the near complete neglect of ZODB/ZEO comes from the fact that indexing was only added recently (as far as I remember). When I tried it about a year ago, I ran into some inconsistencies. But these are probably fixed by now. > > ...Edmund. > Stephan > > > ------------------------------------------------------- > This sf.net email is sponsored by:ThinkGeek > Welcome to geek heaven. > http://thinkgeek.com/sf > _______________________________________________ > Webware-discuss mailing list > Web...@li... > https://lists.sourceforge.net/lists/listinfo/webware-discuss |
From: Ian B. <ia...@co...> - 2003-02-28 21:09:37
|
On Fri, 2003-02-28 at 09:37, Edmund Lian wrote: > I have a question... please don't get offended by it, I don't mean it to be > offensive... No one should be offended by such a question... > While I'm not a great fan of object oriented DBs, I do see a role for them > in providing persistence when the demands of an application are lightweight > (and don't require all the good stuff that relational DBs offer). I was > reading one of Kuchling's write-ups about ZODB and ZEO last night > (http://www.amk.ca/zodb/zodb-zeo.html), and was wondering why people use > MiddleKit instead of ZODB. I would have answered like Chuck answered, so I won't repeat that. But I'd add that I think ZODB is about as much like an RDBMS as a file system is like an RDBMS. They all store data, and in various ways they can all be used for persistence. A *lot* of people use Zope with a RDBMS. There's benefits to both of them, and certain places where one works better than the other. Most of the places where Zope uses ZODB, a Webware developer will be using a file -- storing servlets, config files, maybe pickling data that's resistent to normalization, etc. While you could use ZODB with Webware, I don't think it fits into Webware's style. It's this opaque persistent pile of objects, where Webware components are usually fairly simple, avoid interrelation where they can, and are recreated on demand. Classes persist in Webware -- and they persist just fine as Python source -- but instances are ephemeral. Ian |
From: Chad W. <ch...@wo...> - 2003-02-28 21:37:22
|
On Fri, 2003-02-28 at 09:37, Edmund Lian wrote: > I was reading one of Kuchling's write-ups about ZODB and ZEO last > night (http://www.amk.ca/zodb/zodb-zeo.html), and was wondering why > people use MiddleKit instead of ZODB. Simplicity, interactivity with an often required RDBMS, and speed. The last time I looked at ZODB (which was well over six months ago), I was horrified by the speed hit you take as compared to an RDBMS solution. Regardless, developers are sometimes not given the option to choose between OODB's and RDBMS'. MiddleKit's Object to Relation mapping is effective and it's simple. It's very much like one of the Java tools that came out of the Enhydra.org project: DODS. Define the classes and their members in a text file and then compile the class files from that definition. It's very slick for starting a project out quickly. I had always wanted to write an Object to Proxy mapping class, agnostic of the data source target. MiddleKit and DODS were close to this, and it made things quite comfortable for me. Alas, I haven't had much time for pet projects, and my current position keeps me away from programming anything heavier than a lightweight shell script. *grin* -- Chad Walstrom <ch...@wo...> http://www.wookimus.net/ assert(expired(knowledge)); /* core dump */ |
From: John H. <jho...@to...> - 2003-02-28 21:49:58
|
I'm going to jump in here though I know I'm _way_ out of my league replying to Chuck and Ian....I'm just a hacker who likes Webware.... I got interested in ZODB and tinkered with it some, and also saw that it could play nice with Webware. It seems to me it could be a nice combination for situations where instances _do_ need to persist. I think the existence of MiddleKit is an indication that there is a need for persistent object instances in Webwrae. If you want your business logic in OOP, ZODB makes it easy to just store and retrieve the objects with little effort. You can use the ZEO part to run an object store accessed through network calls that can handle multiple clients, which seems a big step up from pickling to a file. And if you change your object model you don't have to rework a mapping to an RDBMS. I'll admit I haven't tried MiddleKit but it looks less clean and simple. I think it might be a great job on a problem (mapping objects to RDBMS) that is inherently awkward. The performance may be better, I have no idea. I don't really like Zope much but the ZODB seems the best part of it to me. John Holland > On Fri, 2003-02-28 at 09:37, Edmund Lian wrote: >> I have a question... please don't get offended by it, I don't mean it >> to be offensive... > > No one should be offended by such a question... > >> While I'm not a great fan of object oriented DBs, I do see a role for >> them in providing persistence when the demands of an application are >> lightweight (and don't require all the good stuff that relational DBs >> offer). I was reading one of Kuchling's write-ups about ZODB and ZEO >> last night (http://www.amk.ca/zodb/zodb-zeo.html), and was wondering >> why people use MiddleKit instead of ZODB. > > I would have answered like Chuck answered, so I won't repeat that. But > I'd add that I think ZODB is about as much like an RDBMS as a file > system is like an RDBMS. They all store data, and in various ways they > can all be used for persistence. > > A *lot* of people use Zope with a RDBMS. There's benefits to both of > them, and certain places where one works better than the other. Most of > the places where Zope uses ZODB, a Webware developer will be using a > file -- storing servlets, config files, maybe pickling data that's > resistent to normalization, etc. > > While you could use ZODB with Webware, I don't think it fits into > Webware's style. It's this opaque persistent pile of objects, where > Webware components are usually fairly simple, avoid interrelation where > they can, and are recreated on demand. Classes persist in Webware -- > and they persist just fine as Python source -- but instances are > ephemeral. > > Ian > > > > > ------------------------------------------------------- > This sf.net email is sponsored by:ThinkGeek > Welcome to geek heaven. > http://thinkgeek.com/sf > _______________________________________________ > Webware-discuss mailing list > Web...@li... > https://lists.sourceforge.net/lists/listinfo/webware-discuss |