Did you take a look at McKoi? http://www.mckoi.com/database/
>From the DOC: ============= There are four transaction isolation levels defined by the SQL standard. Each isolation level provides varying degrees of protection from seeing changes made by concurrent connections. The Mckoi database engine supports the strongest isolation level defined by the standard - TRANSACTION_SERIALIZABLE. This isolation level prevents a transaction from seeing all types of concurrent changes. The Mckoi database engine achieves this through a multi-version data model that efficiently manages and isolates multiple views of the underlying data. During a transaction the connection sees a version (or snapshot) of the database that is isolated from any changes made by other connections. Additionally, any changes made within the context of a transaction are isolated from the rest of the database. This means that while a transaction is open the view a connection has of the database is blind from changes made by other concurrent connections. The multi-version data model allows the Mckoi database engine to avoid all inter-transactional table/row locking and deadlock issues. No tables or rows are locked between concurrent transactions. While one transaction is reading from a table, another transaction may update the table at the same time. Any data consistency conflicts (for example, two connections committing a change that deletes the same row from a table) are detected when a transaction is committed. > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > Behalf Of Bill Burke > Sent: samedi, 29. mars 2003 19:00 > To: [EMAIL PROTECTED] > Subject: RE: [JBoss-dev] hsqldb options > > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] > Behalf Of David > > Jencks > > Sent: Saturday, March 29, 2003 10:55 AM > > To: [EMAIL PROTECTED] > > Subject: [JBoss-dev] hsqldb options > > > > > > Prompted by a customer, I did some experiments with hsqldb options. > > > > Currently we specify a tcp port and require a hsqldb mbean > to start the > > hsqldb server. This opens a port and requires explicit > hsqldb shutdown. > > > > Two other options that appear to work are: > > > > specify url jdbc:hsqldb:. and remove the hsqldb mbean. > This results in a > > totally in memory db, nothing saved to disk. IMO this is > appropriate for > > most of the testsuite since it eliminates problems with > data not being > > cleaned up between test runs. > > > > specify url jdbc:hsqldb:somefile and remove the hsqldb mbean. > > This results > > in the db saved in a couple of files named like somefile. > No port is > > opened. No explicit shutdown of hsqldb seems to be > required (although I > > didn't test how much data is actually saved) > > > > Could someone who knows more about hsqldb please explain > clearly why we > > would want to continue using the setup we have now rather > than one of the > > tcp-port free options? > > > > > Man, if only hsqldb was transactional. We should recruit > them to become a > JBoss project and put keen transactional minds like David > Jencks on the > subject. A fully transactional in-memory DBMS would kick the > crap out of > everybody in benchmarking. I'm surprise Oracle 9iAS doesn't > run in-process > with the Oracle DBMS already.... > > Bill > > > > ------------------------------------------------------- > This SF.net email is sponsored by: > The Definitive IT and Networking Event. Be There! > NetWorld+Interop Las Vegas 2003 -- Register today! > http://ads.sourceforge.net/cgi-bin/redirect.pl?keyn0001en > _______________________________________________ > Jboss-development mailing list > [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/jboss-development > ------------------------------------------------------- This SF.net email is sponsored by: The Definitive IT and Networking Event. Be There! NetWorld+Interop Las Vegas 2003 -- Register today! http://ads.sourceforge.net/cgi-bin/redirect.pl?keyn0001en _______________________________________________ Jboss-development mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jboss-development
