Learn something new every day... http://otn.oracle.co.kr/docs/Oracle817/java.817/a83724/resltse1.htm#1017614
Steven is correct, in that the db doesn't implement scrollable cursors, so the Oracle solution is dependent on client side caching. It isn't clear to me how fast the cache gets filled, ie all at once or in response to movement. In our case we are paging and seldom ever iterate more than a few percentage points of a large set. Perhaps that explains our ignorant happiness? So we obviously need to look at OracleResultSetCache as well. Thanks Steven. > -----Original Message----- > From: Ebersole, Steven [mailto:[EMAIL PROTECTED] > Sent: Tuesday, March 25, 2003 12:57 PM > To: 'OJB Users List' > Subject: RE: Using setStartAtIndex with Oracle 8i > > > Oracle 8i (and previous) does _not_ support scrollable > cursors. Thus, the > entire result set is transferred into a client-side memory > cache for result > sets declared as scrollable. All result set methods are then executed > against this memory cache. Obviously, for very large cursors > this will be > very inefficient. > > Your best options are: > 1) Don't use scrollable result sets; > 2) Implement a better client-side cursor cache ( see the > javadocs for the > OracleResultSetCache interface for more details) > > > > > |-----Original Message----- > |From: Matthew Baird [mailto:[EMAIL PROTECTED] > |Sent: Tuesday, March 25, 2003 11:40 AM > |To: OJB Users List > |Subject: RE: Using setStartAtIndex with Oracle 8i > | > | > |are there any oracle experts that could shed some light on this. > | > |the actual code should not bring back all the results and > |only return a subset, but rather it should use the > |ResultSet.absolute method to bop around and only retrieve > |the objects it needs. This code is in RsIterator and > |PersistenceBrokerImpl > | > |anyone? > | > |-----Original Message----- > |From: [EMAIL PROTECTED] > |[mailto:[EMAIL PROTECTED] > |Sent: Tuesday, March 25, 2003 9:29 AM > |To: OJB Users List > |Subject: RE: Using setStartAtIndex with Oracle 8i > | > | > | > |Hi, > | > |I think when you use setStartIndex method, all the results > |are retrieved > |from DB and then your query returns only the subset that > |you specified. > |I ran into that problem too and I had to add an additional > |criteria to my > |query : > | > |Criteria crit = new Criteria(); > |crit.addSql("rownum < 100"); > |Query q = QueryFactory.newQuery(Foo.class, crit); > |Collection c = broker.getCollectionByQuery(q); > | > |The problem is that it uses oracle specific stuff. > |But at least, performance is much better ! > |Hope that helps, > | > |Thomas > | > | > | > |----------------------------------------------------------- > |---------- > |To unsubscribe, e-mail: [EMAIL PROTECTED] > |For additional commands, e-mail: [EMAIL PROTECTED] > | > | > |----------------------------------------------------------- > |---------- > |To unsubscribe, e-mail: [EMAIL PROTECTED] > |For additional commands, e-mail: [EMAIL PROTECTED] > | > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
