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Re: LMDB b-tree question

Kristoffer Sjögren wrote:

Thanks Howard. It wasn't immediately evident in the wording
that MDB_stat use an exclusive b-tree.

Is there some way of estimating the depth of the b-tree based on
database size, number of entries or other metrics?


????

mdb_stat already reports the depth of the tree.


On Wed, Feb 11, 2015 at 6:38 PM, Howard Chu <hyc@symas.com
<mailto:hyc@symas.com>> wrote:

    Kristoffer Sjögren wrote:

        Hi

        Does every database consist of a separate b-tree or is
        "database" just a
        name spacing convince? I.e. are reads faster for many smaller
        databases
        rather than one large database?


    As the documentation says, named databases are separate b-trees.
    Reads may be slightly faster, sure, but not by much. You need to
    have enough separate DBs to reduce the overall tree height of the
    equivalent combined tree to see a measurable difference.




--
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/