Lennart Petersson wrote: > Sound like a fucking stupid dummy question, but what the hell...
> What is having the best performance? > 1) To let the DB generate next key using some kind of IDENTITY/SEQUENCE function? > 2) To do like we do today and many others i guess, something like the HIGH/LOW key >generator in Castor. We have > a CMP EB that handle this table. > Any ideas? Oleg, what have you seen in the Castor work? > /Lennart A fucking stupid dummy answer: IMHO the best performance is with UUID key generator, but it requires primary key char[30], such keys work slower than numeric ones. HIGH/LOW key generator has a parameter "grab-size" - how many numbers to "grab" during one database operation. The more is grab-size the more is performance, but also more is the average gap in a sequence of generated keys. With low grab-size it's slower than IDENTITY/SEQUENCE, with high grab-size it's faster, I don't know the threshold value. IDENTITY/SEQUENCE key generators have good performance and almost no gaps, but they are not portable across different RDBMS. My choice is HIGH/LOW. Oleg > Den 2002-01-14 19:11:05 skrev Dain Sundstrom <[EMAIL PROTECTED]>: >>Cool. I think we should look at using this post beta. >> >>-dain >> >>> -----Original Message----- >>> From: Oleg Nitz [mailto:[EMAIL PROTECTED]] >>> Sent: Monday, January 14, 2002 10:23 AM >>> To: Dain Sundstrom >>> Subject: Re: [JBoss-dev] Autogenerated primary keys etc >>> >>> >>> Dain Sundstrom wrote: >>> > If you want to write the code for the most popular data >>> bases, I'll attempt >>> > to write a plugable engine for it. >>> The code is already written in Castor and can be easily reused. >>> There is KeyGenerator interface that can be used independently from >>> other CastorJDO code. >>> And the castor.jar is bundled with JBoss 3.0, isn't it? >>> And Castor KeyGenerators are well tested, don't reinvent the wheel :) >>> >>> Oleg >>> >>> > -dain >>> > _______________________________________________ > Jboss-development mailing list > [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/jboss-development _______________________________________________ Jboss-development mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jboss-development
