vms_tdb rewrite

[Dave Jones]

>I have only one question: what do you think should be best parameters for
>the vms_tdb_default.conf file ? My first guess is that the default 9 bits
>mask size should be good for most files of most sites.

My impression is that most files have few records and don't change much, so
the mask size doesn't make that much difference.  The number of active records
in the few 'busy' files would seem to vary greatly with the number of clients,
but I imagine a smaller mask size would work a little better for most sites.

The major penalty for too large a mask size is that it tends to accumulate more
'deleted' records, so tdb_traverse slows down some.  Having too small a hash
mask slows down fetch and store operations as you get more records in the same
hash chain.

-------------------------------------------------------------------------------
David L. Jones               |      Phone:    (614) 292-6929
Ohio State University        |      Internet:
140 W. 19th St. Rm. 231a     |               jonesd at er6s1.eng.ohio-state.edu
Columbus, OH 43210           |               vman+ at osu.edu

Disclaimer: I'm looking for marbles all day long.