Version 3.0.1
In-memory databases

The wiredtiger_open in_memory configuration changes WiredTiger to run in cache without writing to a backing disk. Data is limited to the configured cache size.

If in_memory is configured, WT_CURSOR::insert and WT_CURSOR::update methods may return an additional error, WT_CACHE_FULL, indicating the insert or update operation requires more than the configured cache size to complete. If a transaction is in progress, it should be rolled back.