Ontopia 5.0.0 enabled a new tolog optimizer by default, a move we knew risked causing difficulties for customers. One customer (NRK/Skole) has reported that they suspect this change caused problems for their application following the upgrade.
It is possible to control which optimizers are turned on and off in queries by including a comment in a special syntax. Unfortunately, in order for NRK to turn off the new optimizer in their application, they need to add that OPTION string to every single query in their application, since in 5.0.0 there is no way to set the option globally.
To avoid this, revision 450 implements a file called tolog.properties. This is a normal Java properties file, loaded from the classpath. In the new version, options in the query take precedence over options in tolog.properties, which again take precedence over the defaults.
This means you can now control properties globally for your application, should you wish to. If there is no tolog.properties everything will work as before.