Automatic write to disk option?

Question

Hi there,
I was just wondering, is there any sort of option in TimesTen that flushes changes to the database to disk, as soon as possible? Such an option might be useful in failure situations, say, if a server crashes or has a power failure, to minimize the amount of lost changes, though at a possible cost in performance.

Answer 1

TimesTen provides the full ACID properties you can use, and DurableCommit is an attribute you can set for your connection; but as you said, it's at a major cost of performance. There is also a built-in procedure called ttDurableCommit that can be called from the application. Calling this builtin flushes the current transaction and all previously committed transactions in the transaction log buffer to disk.
Note that the transaction log manager has a background log flusher that continuously flushes the transaction log data to disk as fast as it can, so you don't really need to do the periodic durablecommit calls yourself.
For high availability, you can use Replication 2-SAFE to ensure no-data-loss with any single point of failure. Using Replication 2SAFE is actually faster than using durable commit on every transaction.
Using DurableCommit to guard against data loss due to power failure is NOT a good use of TimesTen.
Susan