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?
Cheers, -Kristoffer
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.
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?
On Wed, Feb 11, 2015 at 6:38 PM, Howard Chu 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/
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.
openldap-technical@openldap.org
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Howard Chu -
Kristoffer Sjögren