Sorry, just had a brain camp in the morning. Over time the BI usually reaches a certain high water mark and should not grow any bigger unless there are some unexpected things (like an usual high transaction load or unexpectedly long running transactions). In such a case the BI would grow bigger than usual. Depending on how your system is laid out the BI might reach some limit (for example filling the file system) which causes the database to shut down abnormally when it can't write to the BI anymore. In order to prevent that from happening, for one you can limit on the BI so that it can't grow any bigger before such a limit is reached. Secondly, in order to prevent the database from shutting down abnormally you can use BI stall so that it goes in a read-only mode instead. This should give you time to be able to analyze and fix the root cause.
Heavy Regards, RealHeavyDude.