There is no recovery mechanism for the cache in which DBQL row values are collected. During a restart, any rows in cache that were not sent to the AMPs are lost. However, query logging is not aborted as a result of a restart; DBQL uses the contents of DBQLRuleTbl to continue logging.
For information on flushing the DBQL cache information to the logs, see Options for Flushing the DBQL Cache and Flushing the DBQL Caches Manually.
Protection for a Committed Row
DBQL tables occupy permanent space in database DBC. Therefore, once a row has been sent to an AMP, its insertion into a DBQL log is safeguarded through the transaction and recovery journaling process.
In addition, the data in every DBQL table is protected with FALLBACK. Therefore, the data is available unless two or more AMPs in the same clique fail simultaneously.