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From "George Aroush" <>
Subject RE: Question about query performance degredation
Date Wed, 01 Nov 2006 23:23:53 GMT
Hi Andy,

Yes, please, let us know how it goes when you optimize.  If that doesn't
help, after optimizing, stop indexing for a bit.  Even a better stop the
indexer application, and re-start the searcher.  I.e.: a reboot of your
application with the indexer out of your way.


-- George Aroush

-----Original Message-----
From: Andy Berryman [] 
Sent: Wednesday, November 01, 2006 9:29 AM
Subject: Re: Question about query performance degredation

I'm maintaining the index at a pretty constant rate throughout the day.
Right now its possible that at least 1 document is getting updated every 10
minutes.  (The background process I am using runs every 10 minutes to look
for changes that need to be indexed.)

I my specific case ... For a document that I need to "update" in the index
... I make a call to delete the document first and then I create a new
document (with the updated info from the database) and add it into the

As for optimizing ... Currently I am not making any calls to "Optimize()".

So I guess your first suggestion would be to optimize the index and check
the query performance after that?


On 10/31/06, George Aroush <> wrote:
> Hi Andy,
> I believe you are on the right track, index fragmentation maybe your 
> issue.
> How frequently are you updating the index, vs. how frequently are you 
> optimizing it?  Is the update adding new documents vs. modifying 
> existing documents?
> If after optimizing you still don't get back the original performance, 
> stop indexing for a bit and see if search gets better.
> If fragmentation is your issue, I have some suggestions that may work 
> for you.
> Regards,
> -- George
> -----Original Message-----
> From: Andy Berryman []
> Sent: Tuesday, October 31, 2006 1:25 PM
> To:;
> Subject: Question about query performance degredation
> I have a scenario where I'm seeing the performance (specifically time) 
> of searches against my index degrade on a daily basis.  The amount of 
> time it is taking to load the index is staying fairly constant 
> however.  This is a fairly large index.  It has over a million documents
in it.
> The scenario I have is that I'm maintaining the index from data in the 
> database ... and I'm doing so on onstant basis.  So essentially as 
> changes are made in the database I have a background task that updates the
> So I'm supporting concurrent readers and writers on a constant basis 
> throughout the day.  I'm NOT using compound files.  During my 
> development and testing, the use of compound files caused a 
> significant increase in Disk I/O usage and caused the maintenance of 
> the index to take much longer.  As such ... I decided against them.
> My thoughts are that the reason the search is taking longer is because 
> the index files are getting more and more "fragmented" over time 
> because I'm not using the compound files.  And that's why the searches 
> are taking longer.
> Thoughts?
> Thanks
> Andy

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