[CWB] Re: Re: How to remove the corpus data files from cache?

[Petrakis Stefanos]

Hallo Stefan and list members,


> On 21 Jan 2008, at 17:51, Petrakis Stefanos wrote:
> 
> > Any idea how can I un-cache/remove the corpus data files 
> from memory?
> > I want to run some tests on a "cold" cache to check time 
> performance 
> > to compare the timing differences on my server between the 
> cqp client 
> > and a simple perl script running the same queries.
> 
> There's no standard way of clearing the disk cache, but it 
> may be possible using system-specific commands or special 
> software.  I'm not enough of a Linux expert to help you on 
> this point (you're using Linux, aren't you?), but perhaps 
> someone else on the list has a good idea.
> 

Yes, we are using linux. I talked a bit with our system admins and they don't have a standard/safe way to help me with this (clearing the disk cache).


> >> How large are the corpora on which you've observed this behaviour?
> >> There is absolutely no reason why CQP should take that 
> long on a 5- 
> >> million word corpus.
> >>
> > The size is about 100M .
> 
> At that size, cache warming may have a substantial effect.  
> For instance, on our BNCweb installation, the first queries 
> can take a minute or longer, but once most of the data are in 
> the cache, the results become available within seconds.
> 


Ok, so if the delay you report for BNCweb is more than a minute... Then maybe there is nothing strange with a 20+ seconds delay for cache-warming in our case...
But, this introduces another problem for us, since we cannot expect our users to wait for such a long time.
Really, what do users of the BNCweb say about such long delays?
And what would your suggestion be regarding the user's experience? 
Or, are there other ways to setup CQP so that this delay is eliminated?


And btw, thanks a lot,
This is really great support

lg,
Stefanos