Re: derby.storage.pageCacheSize on multiple databases

[Guillermo Averboch <ac...@gmail.com>]

Knut,

Actually, it does not work. If you set derby.storage.pageCacheSize after 
loading a database, the setting affects that database too. In the end, the last 
setting affects all databases. 

I learned this the hard way, after everybody started complaining about how 
awfully slow the system was...

Guillermo

Re: derby.storage.pageCacheSize on multiple databases

[Kristian Waagan <Kr...@Sun.COM>]

Guillermo Averboch wrote:
> Knut,
> 
> Actually, it does not work. If you set derby.storage.pageCacheSize after 
> loading a database, the setting affects that database too. In the end, the last 
> setting affects all databases. 

Hello Guillermo,

I tried the approach suggested by Knut Anders, and it seemed to work for 
me when I tested it on trunk. I added a trace print in the cache, and 
could see that it got initialized with different values. As the maximum 
size is kept in a final variable, the only way it can change is if the 
database is shutdown and rebooted. Now, this is only valid for the new 
cache implementation, but I would believe the approach should work for 
the old one too.

So, a few question that might help to figure out what is going on:
  a) Are you sure the databases are not rebooted after the initial boot?
  b) Are you sure you set the system property in the VM process that 
boots the databases?
  c) Which driver are you using?

I assume you have written a Java class that boots the databases for you 
and possibly starts the network server?


regards,
-- 
Kristian

> 
> I learned this the hard way, after everybody started complaining about how 
> awfully slow the system was...
> 
> Guillermo
> 
> 
>