On 09/08/14 03:56, Bill Hastings wrote:

Just getting my feet wet with LMDB. Is it possible for multiple threads write into LMDB concurrently?

No. Only one write transaction can be active at a time, and each transaction belongs to one thread. See lmdb.h.

Or should writes be serialized to LMDB?

lmdb does that, so you don't need to.

Except if you use the MDB_NOLOCK flag. Then I think you can use a transaction across threads. But there must still be only one write transaction, and you must enusre that and manage concurrency and synchronization between threads yourself. Likely not what you want, in particular as an LMDB beginner.