lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Grant Ingersoll <>
Subject Re: Multiple Indices vs Single Index
Date Thu, 20 Sep 2007 14:27:21 GMT
If I understand correctly, you want to do a two stage retrieval  
right?  That is, look up in the initial index (3.4 GB) and then do a  
second search on the sub index?  Presumably, you have to manage the  
Searchers, etc. for each of the sub-indexes as well as the big  
index.  This means you have to go through the hits from the first  
search, then route, etc. correct?

Have you tried creating one single index with all the (stored)  
fields, etc?  Worst case scenario, assuming 1GB per index, is you  
would have a 40GB index, but my guess is index compression will  
reduce it more.  Since you are less than that anyway, have you tried  
just the straightforward solution?  Or do you have other requirements  
that force the sub-index solution?  Also, I am not sure it will work,  
but it seems worth a try.  Of course, this also depends on how much  
you expect your indexes to grow.

Also, what was inconclusive about your tests?  Maybe you can describe  
more what you have tried to date?


On Sep 20, 2007, at 3:50 AM, Nikhil Chhaochharia wrote:

> Hi,
> I have about 40 indices which range in size from 10MB to 700MB.   
> There are quite a few stored fields.  To get an idea of the  
> document size, I have about 400k documents in the 700MB index.
> Depending on the query, I choose the index which needs to be  
> searched.  Each query hits only one index.  I was wondering if  
> creating a single index where every document will have the  
> indexname as a field will be more efficient.  I created such an  
> index and it was 3.4 GB in size.  My initial performance tests with  
> it are not conclusive.
> Also, what are the other points to be addressed while deciding  
> between 1 index and 40 indices.
> I have 8GB RAM on the machine.
> Thanks,
> Nikhil
> ---------------------------------------------------------------------
> To unsubscribe, e-mail:
> For additional commands, e-mail:

Grant Ingersoll

Lucene Helpful Hints:

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message