Cache persistence

There’re a few well-written articles on about OBIEE caching configuration and strategies already. However, I’m posting a solution that I’ve found while investigating an unexpected behavior with tpl cache files disappearing for no reason (no updates in polling table, no manual purge, no BI services restart). Here’s the solution from Oracle:

The behavior was resolved when customer modified the refresh interval for the Repository variables that exist in their Repository.
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.

I think they should try to cover similar thing in OBIEE documentation.

2 thoughts on “Cache persistence”

  1. Will the cache get purged if the Repository Variable gets refreshed but its value didnt change after the refresh?

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