Re Tony, 2 Liens interessant sur ces sujets
= Pour ceux qui voudraient quitter Oracle (t as pas un machin comme ca chez toi ? ;)) la BDD daffodildb se dit tres compatibel a tous les niveaux : http://www.theserverside.com/tss? service=direct/0/NewsThread/threadViewer.markNoisy.link&sp=l29777&sp=l145592#144909 ============================ McKoi vs HSQLDB vs Derby vs Daffodil Posted by: Uday Parmar on November 03, 2004 in response to Message #144880 2 replies in this thread bad mash, Have a look at Comparison sheet to see how we compare with other db's. With regards to migration from Oracle, we support most of the syntax and features like sequences, triggers, procedures with PL/SQL. That how we are in the process of making our db compatible with Compiere ERP , with is currently compatible only with Oracle. =========================== = Et la une comparaison particulierement interessante sur HSQLDB et Derby/Cloudscape) : "McKoi vs HSQLDB vs Derby vs Daffodil" http://www.theserverside.com/tss? service=direct/0/NewsThread/threadViewer.markNoisy.link&sp=l29777&sp=l145592#153949 =========================== McKoi vs HSQLDB vs Derby vs Daffodil Posted by: Sunitha K on January 23, 2005 in response to Message #144909 0 replies in this thread Hi, I did a little searching today and I wanted to share my thoughts on this topic of comparisons for hsqldb vs derby.... I believe that it is not a fair apples to apples comparison to be comparing HSQLDB and Apache Derby (aka Cloudscape). There are some important differences in the functionality provided by HSQLDB and Derby which in turn contribute to how they perform. 1) Transactions: HSQLDB does *not* support transaction isolation. All transactions run in read uncommitted ( dirty read mode). Transactions read dirty data ( uncommitted data) which is not what you want in case of update transactions/ lets say a banking application. Derby supports *all* transaction isolation levels. The default tranaction isolation that it runs in is READ_COMMITTED. Derby is guaranteeing that if you run in read committed mode, you will not be reading dirty data. 2) In-memory database: HSQLDB by default creates table in memory , so if you use CREATE TABLE the table is in memory. This means with large amounts of data there is high memory utilization and the application may be limited to the amount of memory available and may perform slow if table does not fit in memory. http://www.jboss.org/wiki/Wiki.jsp?page=ConfigJBossMQDB talks about out of memory errors as a result. http://www.devx.com/IBMCloudscape/Article/21773 this article talks about how this could lead to scalability issues Derby is disk based. Derby uses a page cache to keep recently used pages in memory and writes data to disk. Thus the memory consumption is stable and can be used for large amounts of data. This difference is important to note as the speed in these 2 cases are different. This seems to be reason why it is not ideal to compare speed differences here. 3) Reliability: Derby is guaranteeing that if your system crashes in any way that committed transactions will remain committed. This requires that when a transaction commits, logs are synced to the disk. Syncing to the disk takes time. But on the other hand, it seems like hsqldb is not failsafe as the log file is not flushed (synced) to the disk after a commit. http://nagoya.apache.org/eyebrowse/ReadMsg?listName=derby- [EMAIL PROTECTED]&msgNo=11 http://nagoya.apache.org/eyebrowse/ReadMsg?listName=derby- [EMAIL PROTECTED]&msgNo=13 gives a little more detail on the log flusher thread for hsqldb. Thus it seems necessary to consider these differences before one compares raw numbers. Some links from web on hsqldb and derby: http://forums.atlassian.com/thread.jspa? threadID=6153&messageID=248904679 http://developers.slashdot.org/comments.pl? sid=127289&threshold=1&commentsort=0&tid=221&tid=198&tid=136&tid=108&tid=8&tid=2&mode=thread&pid=10640524#10642178 http://www.luisdelarosa.com/blog/2004/10/whatever_happen.html post by stephane TRAUMAT http://www.jboss.org/wiki/Wiki.jsp?page=ConfigJBossMQDB Sunitha. ============================= Jean Louis Le mardi 01 fÃvrier 2005 à 13:00 +0100, Tony GALMICHE a Ãcrit : > Bonjour Jean Louis, > > ARGENTE Jean Louis a Ãcrit le 31/01/05 20:40 : > > >>> <>Ne vaudrait il pas mieux se focaliser sur le non partage de cete BDD > >>> dans OOo (voir ou cela en est etc.) ? > >> > >Je suis en train de faire des recherches la dessus sur le net, la peche > >n est pas terrible sur ce sujet. > > > >Chez OOo : > >http://dba.openoffice.org/miscellaneous/developer_projects.html#record_locking > > > > > Avec ce document, je viens de constater à ma grande dÃception, que les > requÃtes multi tables ne seront toujours pas possible avec le format > dBase, contrairement à ce que je pensais :-( > > >Lors de mes ballades sur le net pour ces histoires de BDD , ai trouve > >qques petites choses en Java Libre bien sympa, jette un coup d oeil : > > > >Celui la devrait te plaire ;) > >http://www.daffodildb.com/dbreplicator.html > > > > > En effet, c'est intÃressant. > > >avec son pendant, mais non indispensable BDD (et hop ! une BDD libre de > >plus ) : > >http://www.daffodildb.com/onedollardb-opensourcenews.html > >http://www.daffodildb.com/daffodildb.html > >http://www.daffodildb.com/one-dollar-db.html > > > > > Et Firebird, tu en penses quoi, car j'ai testà la semaine derniÃre vite > fait et je l'ai trouvà pas mal, mais je me demandais, pourquoi elle > n'est pas plus utilisÃe / connue ? > > >D autres outils (c est mon jour Java ;): > > > >http://www.trash.net/~ffischer/admin/index.html > > > >http://squirrel-sql.sourceforge.net/ > >http://squirrel-sql.sourceforge.net/kulvir/tutorial.html > > > > > Pas mal aussi. > > >http://jdbcmanager.sourceforge.net/ > > > >http://www.horsman.co.nz/story.do?id=24 > > > >http://basicquery.sourceforge.net/ > > > >http://www.memoriapersistente.pt/en/opensource/gaudi/ > > > > > >MySql pour les nulls ;) > >http://jmvanel.free.fr/mysql-start.html > > > >Compierre fonctionne donc maintenant sans Oracle : > >http://www.daffodildb.com/daffodil-compiere.html > > > > > Interessant aussi, mais c'est quoi cette base de donnÃes Daffodil DB ? > > Merci pour les liens. > > Tony > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > -- Jean Louis Message sans accent pour etre lisible par tous les logiciels de messagerie electronique... --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
