On Oct 3, 2008, at 5:49 PM, Artem Melentyev wrote: > Derby looks like a good choose, even it is probably slower than > hsqldb. > Derby is more powerful than hsqldb in some complex stuff like > transactions, sql fuctions and jdbc extensions. > We should test latest versions to see current performance of Derby. > > Another variant is h2database.com which supposed to be faster than > hsqldb (h2 is fork of hsqldb). But it is less powerful than Derby too. > (no setCatalog) > > So +1 for derby. > > We could try to use db4o, but I think we shouldn't do it now. I > think it > is not worthy effort for now. (new access api, no sql-like language) > I'll try it only after JCRStore will be done. > > Also I would like to propose to use UTF-8 as default encoding for > standalone distribution.
+1 I wanted to send a mail on this. Thanks -Vincent > AFAIK the major issue against utf8 is we can't control some parts like > DB or AppServer which configured for ISO for default (in some > cases :)). > In standalone distribution we control everything, so there are no > problems with utf8. > (note: currently hsqldb and jetty works fine without explicit utf8 > configuration. only xwiki.cfg, web.xml and hibernate.cfg.xml need to > be > configured) > > Vincent Massol wrote: >> <snip> >>> >>> For switching to Derby, I'm not convinced. >> >> I'm very positive for Derby (even though I haven't used it myself a >> lot). It has made lots of progress in the past few years and it's >> production ready, which is definitely NOT the case for HSQLDB. >> >> Performances are very similar to MySQL and other DBs (see link I >> gave). >> >> It supports Catalogs/Schema (AFAIK) so that it will even work with >> multiwiki (which isn't the case for HSQLDB). >> >> DB4O has always been something at the level of research for me but >> then I haven't checked it out for the past 4 years so it's likely it >> has evolved. >> >> But right now Derby makes more sense for us. >> >> I'm not sure at all (I would even say no) that Artem should work on >> this since I haven't heard any request from XWiki users/customers to >> use DB4O and I would prefer that Artem works on some feature that are >> more requested by our users when he's done with JCR/QueryManager. >> >> I don't have the slightest doubt that Derby is better than HSQLDB for >> this use case. Now we could keep our current packaging and just add >> this new one but I think we might just not have enough manpower to >> maintain both so I would keep the HSQLDB one but not make it the >> default so that what we release would be Derby+Jetty+ServiceWrapper. >> >> That said all this is hypothetical for now since I want to finish the >> new rendering before moving to something else so I won't be working >> on >> this anytime soon. Of course if someone else is interested please go >> ahead. >> >> Thanks >> -Vincent >> >>> I don't know if you know >>> about PolePosition, a database benchmarking project. Some older >>> results >>> (I can't seem to find product versions on that site, or a date, but >>> the >>> HTML pages were modified a year ago) shows that HSQL (without >>> Hibernate) >>> is a clear winner, although it manages to do that because it keeps >>> most >>> of the data in memory, so data might be lost if the server is not >>> cleanly shutdown. Here's the page: >>> http://polepos.sourceforge.net/results/html/index.html >>> >>> Some things to notice: >>> - Hibernate adds serious overhead. >>> - When using hibernate, HSQL is faster than MySQL. >>> - A very good storage mechanism would be DB4O, which is also in- >>> java, >>> and which can work directly with objects (an object oriented >>> database). >>> Converting from objects to tables and back is inefficient, and >>> communicating over JDBC adds even more overhead, while storing >>> objects >>> directly is much faster. Also, complex/deep queries are the >>> fastest in >>> this DB (see Barcelona/query, where DB4O is between 67 and 2500 (!) >>> times faster than HSQL+Hibernate, and up to 47000 times faster than >>> Derby *without* Hibernate). Artem, do you think you could try to >>> implement direct DB4O storage after you finish improving storage >>> refactoring and the query manager? >>> - At least in the versions used when this test was made, Derby >>> (JavaDB >>> as it is called here) is among the slowest in most tests. >>> >>> Could someone download PolePosition and run it on recent versions of >>> Derby and HSQLD, with Hibernate in front of them, to get some recent >>> comparison data? _______________________________________________ devs mailing list [email protected] http://lists.xwiki.org/mailman/listinfo/devs
