Tuesday, January 13, 2009

OBIEE Cache persistence

Some good investigation done on Cache persistence (by wildmight? couldn't find the author):


...When a dynamic repository variable is updated, cache is automatically purged. This is designed behavior. Cache will be invalidated (i.e. purged) whenever the initialization block that populates dynamic repository variable is refreshed. The reason that refreshing a variable purges cache is that if a variable was used in a calculation, and the variable changed, then cache would have invalid data. By purging cache when a variable changes, this problem is eliminated.

Since this is the designed functionality, Change Request 12-EOHPZ3 titled ‘Repository variable refresh purges cache’ exists on our database to address a product enhancement request. The workaround is to go through the dynamic repository variables and verify that the variables are being refreshed at the correct interval. If a variable needs to be refreshed daily, there may be a need to set up a cache seeding .bat file that runs after the dynamic variable has been updated. If the cache seeding .bat file runs prior to the refresh of the dynamic variable refresh, then the cache will be lost.

Till Next Time


Kevin said...


I apologize if this is covered elsewhere but do you know where / how the dynamic variable refresh rate is set?


Kevin said...

nm, just remembered that it is controlled by the init block refresh interval...