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Re: [Springframework-developer] DataFieldMaxValueIncrementer
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From: <tri...@tr...> - 2004-02-28 13:17:01
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Juergen, You broke all my existing tests :-) The DriverManagerDataSource now throws a ClassNotFoundException which is a checked exception. It used to rethrow this as an unchecked exception. I can live with this change, but do we want to change this behavior at this point? As for the Incrementers - I'm going totest them today. Thomas Quoting "jürgen höller [werk3AT]" <jue...@we...>: > I've committed the revised DataFieldMaxValueIncrementer hierarchy. There = > is a new AbstractSequenceMaxValueIncrementer now, with no value cache = > anymore. OracleSequenceMaxValueIncrementer and = > PostgreSQLSequenceMaxValueIncrementer are very simple classes of this = > new base class. In general, there's significantly less code involved = > than before. > =20 > I've decided to implement AbstractSequenceMaxValueIncrementer based on = > plain JDBC, to be able to throw proper sequence-related exceptions. A = > queryForLong wouldn't be a particularly useful extension of = > JdbcTemplate, and it would throw DataAccessApiUsageExceptions if no row = > found or the like - not appropriate when the user didn't specify the = > query in the first place. > =20 > I've also written unit tests for all incrementers. I just did a live = > test of HsqlMaxValueIncrementer; gonna test MySQLMaxValueIncrementer = > later today. Dmitriy, Thomas, could you have a look at the revision, and = > test OracleSequenceMaxValueIncrementer (and possibly = > PostgreSQLSequenceMaxValueIncrementer). > =20 > Juergen > =20 > > ________________________________ > > Von: spr...@li... im Auftrag = > von Dmitriy Kopylenko > Gesendet: Do 26.02.2004 14:33 > An: spr...@li... > Betreff: RE: [Springframework-developer] DataFieldMaxValueIncrementer > > > > +1 for removing cache from sequence-based incrementers > > -----Original Message----- > From: spr...@li... > [mailto:spr...@li...] On Behalf = > Of > j=FCrgen h=F6ller [werk3AT] > Sent: Thursday, February 26, 2004 2:43 AM > To: spr...@li...; > spr...@li... > Subject: Re: [Springframework-developer] DataFieldMaxValueIncrementer > > > Actually, MySQLMaxValueIncrementer does leverage the value cache in a > meaningful way, and HsqlMaxValueIncrementer at least just issues a = > single > delete for the entire advance cache. But the sequence-based = > incrementers, > i.e. OracleSequenceMaxValueIncrementer and the new > PostgreSQLSequenceMaxValueIncrementer do not benefit from the value = > cache at > all. So I just suggest to remove the value cache from the sequence-based > incrementers. > > Juergen > > > ________________________________ > > Von: spr...@li... im Auftrag = > von > j=FCrgen h=F6ller [werk3AT] > Gesendet: Do 26.02.2004 08:25 > An: spr...@li... > Betreff: Re: [Springframework-developer] DataFieldMaxValueIncrementer > > > > I'm done with the simplicication so far - less than half of the code = > remains > ;-) > > However, there's still the value cache. I strongly doubt that this is a = > good > idea, particularly with database sequences. Essentially, if the cache = > size > is 10, we're accessing the sequence 10 times in advance instead of = > asking in > whenever an id is requested. There's the same amount of SQL statements > involved; what's the benefit here? > > The drawback is that we need to synchronize cache access for this. If we > simply went straight to the database sequence for each id, we could = > delegate > concurrency to the database. And I don't know of an O/R mapping tool = > that > does such sequence value caching (please correct me if I'm wrong). All > things considered, I suggest to drop the value cache completely. > > Juergen > > > ________________________________ > > Von: spr...@li... im Auftrag = > von > tri...@tr... > Gesendet: Mi 25.02.2004 23:02 > An: spr...@li... > Betreff: Re: [Springframework-developer] DataFieldMaxValueIncrementer > > > > > +1 > > I never understood the need for a double as an incrementer anyway. = > Simple > is better. The OracleSequenceMaxValueIncrementer could use some = > refactoring > too. We don't need a SqlFunction - we should be able to use the new > queryForXxxx methods on the JDBC Template. Once you check in your = > changes, > I can take a look at the Oracle one. > > Thomas > > Quoting "j=FCrgen h=F6ller [werk3AT]" <jue...@we...>: > > > I've added PostgreSQLSequenceMaxValueIncrementer today, as attached to > > =3D our JIRA. On the occasion, I've reviewed the incrementer =3D > > implementations: They're too complicated for what they achieve, =3D > > IMO.Thus, I've dropped the inner class NextMaxValueProviders and moved > > =3D the code to the DataFieldMaxValueIncrementer class hierarchy = > itself. > > =3D20 I've noticed that AbstractDataFieldMaxValueIncrementer's > > nextDoubleValue =3D effectively returns an integer, like > > nextIntValue/nextLongValue - after =3D all, the template method > > getNextKey returns a long, so there's no chance =3D for a true double. > > Thus, I see no point in keeping the nextDoubleValue =3D method in the > > DataFieldMaxValueIncrementer interface; all current =3D = > implementations > > do not return doubles here. =3D20 > > Furthermore, why does getNextKey take a type parameter when it returns = > a =3D > > long anyway? Any JDBC driver will let you read both an int and a long = > =3D > > via rs.getLong, so there's no point in that type parameter. Simply =3D > > reading the value via getLong should be sufficient. > > =3D20 > > This leaves a very simple DataFieldMaxValueIncrementer interface with = > =3D > > nextIntValue, nextLongValue and nextStringValue methods, with =3D > > implementations that achieve their goal in a straightforward fashion. = > =3D > > AbstractDataFieldMaxValueIncrementer delegates all three to getNextKey = > =3D > > which returns a long, casting the long to an int respectively = > converting =3D > > it to a string with optional padding. > > =3D20 > > This should still cover all current usages and therefore not break =3D > > compatibility, and it should make it as easy as possible to implement = > an =3D > > AbstractDataFieldMaxValueIncrementer subclass for a specific database. = > =3D > > Thomas, Dmitrity, what do you think? > > =3D20 > > Juergen > > =3D20 > > P.S.: > > Obviously, 1.0 RC2 won't be released tonight but rather at the end of = > =3D > > the week. I believe it's worth it, as I'd also like to wait for = > feedback =3D > > on the other recent changes. > > =3D20 > > > > > > ------------------------------------------------------- > > SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and > > deploy apps & Web services for Linux with a free DVD software kit from > > IBM. Click Now! = > http://ads.osdn.com/?ad_id=3D1356&alloc_id=3D3438&op=3Dclick > > _______________________________________________ > > Springframework-developer mailing list > > Spr...@li... > > https://lists.sourceforge.net/lists/listinfo/springframework-developer > > > > > > > > ------------------------------------------------------- > SF.Net is sponsored by: Speed Start Your Linux Apps Now. > Build and deploy apps & Web services for Linux with > a free DVD software kit from IBM. Click Now! > http://ads.osdn.com/?ad_id=3D1356&alloc_id=3D3438&op=3Dclick > _______________________________________________ > Springframework-developer mailing list > Spr...@li... > https://lists.sourceforge.net/lists/listinfo/springframework-developer > > > > > ------------------------------------------------------- > SF.Net is sponsored by: Speed Start Your Linux Apps Now. > Build and deploy apps & Web services for Linux with > a free DVD software kit from IBM. Click Now! > http://ads.osdn.com/?ad_id=1356&alloc_id438&op=3Dick > _______________________________________________ > Springframework-developer mailing list > Spr...@li... > https://lists.sourceforge.net/lists/listinfo/springframework-developer > > > > > ------------------------------------------------------- > SF.Net is sponsored by: Speed Start Your Linux Apps Now. > Build and deploy apps & Web services for Linux with > a free DVD software kit from IBM. Click Now! > http://ads.osdn.com/?ad_id=1356&alloc_id438&op=3Dclick > _______________________________________________ > Springframework-developer mailing list > Spr...@li... > https://lists.sourceforge.net/lists/listinfo/springframework-developer > > > > ------------------------------------------------------- > SF.Net is sponsored by: Speed Start Your Linux Apps Now. > Build and deploy apps & Web services for Linux with > a free DVD software kit from IBM. Click Now! > http://ads.osdn.com/?ad_id=1356&alloc_id438&op=3Dick > _______________________________________________ > Springframework-developer mailing list > Spr...@li... > https://lists.sourceforge.net/lists/listinfo/springframework-developer > > > > > ------------------------------------------------------- > SF.Net is sponsored by: Speed Start Your Linux Apps Now. > Build and deploy apps & Web services for Linux with > a free DVD software kit from IBM. Click Now! > http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click > _______________________________________________ > Springframework-developer mailing list > Spr...@li... > https://lists.sourceforge.net/lists/listinfo/springframework-developer > |
