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Tests were run to compare the new Delayed Durability transaction mode with the existing transaction processing mode using DELAYED_DURABILITY 1, allowing the log sync to be deferred for 1 second. The results indicated that the new Delayed Durability achieved performance gains of a factor of 2 to 3 over the previous transaction processing. A setting of 1 second is recommended because it is enough for a good performance gain and higher values offer very little additional benefit.
The chart below shows performance of the new Deferred Durability transaction mode (red) and the existing standard transaction processing mode (blue):
The data was acquired using the FairCom cttpca test. This test was run for 30 seconds using server DLL with varying numbers of connections. New files were created before each test run. For this test, c‑tree data and index caches were large enough to hold all records and index nodes.
The existing transaction processing is referred to as "full recoverability" because all transactions can be recovered. The new Deferred Durability technique can be used with Restore Points to allow the data to be rolled back to a known good state.
