edx/edx-ora — pull request #133 by VikParuchuri (2013-08-29 21:21:53+00:00)
Title: Reduce ORA cpu usage by caching some expensive queries

Currently, the ML grader will call the ORA server at 5 second intervals looking for grading to do. This causes ORA to execute somewhat expensive queries once every 5 seconds. This PR avoids that by caching the result of the expensive query and recalculating it at longer intervals.