Re: RE : [mdr-users] [ann] JDBC storage contributed

I just got CVS access, so once I have applied some updates/fixes I made 
after sending in the original contribution, I will post a full 
announcement.  In the meantime:

Olivier RICHAUD wrote:
> Is there any documentation on how to use it? By the way, does it come with
> the nightly build of the standalone MDR?

Documentation is in
mdr/extras/jdbcstorage/src/org/netbeans/mdr/persistence/jdbcimpl/package.html. 
  Note that one of the user-visible fixes I'm going to submit based on 
Martin's feedback is to add the standard "MDRStorageProperty" prefix to 
all of the property names.

I don't know about the standalone MDR.

> Another point, is it slower than the native implementation that MDR uses?

Yes.  The amount of slowdown depends on the DBMS configuration.  I 
haven't yet run MDR's own performance tests, but here are some numbers 
from my own informal testing (instantiating the repository MOF extent, 
which involves heavy storage access):

- with MDR BTrees:  7 seconds
- with in-process Java database hsqldb:  9 seconds
- with out-of-process PostgreSQL running on same machine:  15 seconds
- with remote PostgreSQL running across my home wireless LAN:  way too 
long (it's been a while, but I think it was over two minutes)

So for out-of-process use, a lot of tuning work remains to be done.  I'm 
guessing a big improvement will come from using batch writes to reduce 
round-trips.

JVS