[openssl-users] LMDB use of sparse or non-sparse data file

[Geoff Swan]

Sorry, wrong mailing list!

On 22/03/2015 10:47 AM, Geoff Swan wrote:
> I had to duplicate an LMDB database for replication recently, and used
> mdb_copy to do so.
> One server is using the original data.mdb database (which is sparse) and
> the other is using the mdb_copy non-sparse data.mdb file.
> The two servers are identical (hardware, OS, software and
> configuration). OpenLDAP-2.4.39 is being used, 64 bit Linux OS.
> mdb_stat shows the map size as the same, which is expected.
>
> Will the use of the non-sparse file cause any performance issues?
>
> The reason for asking is that I am seeing a difference in search times
> between the two.
> With 20 million objects, a search on modifyTimestamp (which is indexed)
> gives:
> server 1: approx 1s
> server 2: approx 60s
>
> server 2 started with the same search time as server 1 when the
> databases were originally copied, but has slowly increased its search
> time over about a week for this same search.