jackrabbit-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jukka Zitting <jukka.zitt...@gmail.com>
Subject Re: ids and locality
Date Wed, 12 Jan 2011 10:04:13 GMT

On Wed, Jan 12, 2011 at 9:29 AM, Thomas Mueller <mueller@adobe.com> wrote:
> No. In fact, using a persistence manager that stores the *data* in an
> append only way, the main performance problem (more than 80%) is index
> access (for large repositories).

Why don't you simply keep the entire index in memory? You should be
able to squeeze an index entry with all the overhead to something like
32 bytes (for example 16 bytes for the node id, 8 for storage location
and 8 bytes for other data). That's just 32MB for a repository with a
million nodes. Big database servers nowadays come with hundreds of
gigabytes of memory, so even the 3GB memory cost for a repository with
a hundred million nodes is not excessive.


Jukka Zitting

View raw message