Re: Using LMDB without memory mapped files

[Hallvard Breien Furuseth <h.b.furuseth@usit.uio.no>]

On 20. jan. 2016 12:48, José Felix Torre Santos wrote:
> I am using LMDB in an investigation project. It works perfectly with
> persistence and concurrent processes. But in some occasions I want to run an
> standalone process without persistence and as fast as possible. I could do it
> with other binary-tree libraries written in C, but I’d like not to rewrite mi
> code.

Remove the database file if present before mdb_env_open(), and after
mdb_env_close() to clean up.  Enable environment option MDB_NOSYNC.
And maybe MDB_WRITEMAP, but note its documented disadvantages.

> Is there any way to configure or modify LMDB code to work in main memory
> instead memory mapped files?

No such option, and a tweaking the code would be cumbersome in places.
Use an in-memory filesystem, like tmpfs on Linux.  (Not the same as /tmp,
but sometimes /tmp uses tmpfs.)  tmpfs still swaps to disk, though.

--
Hallvard