Re: bdb bad performance again (really need help)

[Quanah Gibson-Mount <quanah@stanford.edu>]

--On Monday, November 10, 2003 8:10 AM +0100 Stefan Metzmacher 
<metze@metzemix.de> wrote:

> > We do not put our entire DB into memory, however, we do run a very large
> > cache (2.5GB).
> >
> > The reason is essentially this -- If you do not have a sufficient cache
> > size, the system must read almost continuously from disk to answer
> > queries. This trashes the disk, and eventually has the end effect of
> > corrupting the database.
>
> How can read operations corrupt the data base?

I don't explain it, I just know what has happened for us, and plenty of 
other sites as well.  I think it is more that BDB's disk cache gets 
corrupted, more than the underlying database files.

--Quanah

--
Quanah Gibson-Mount
Principal Software Developer
ITSS/TSS/Computing Systems
ITSS/TSS/Infrastructure Operations
Stanford University
GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html