lucene-solr-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Fuad Efendi" <f...@efendi.ca>
Subject RE: Lucene FieldCache memory requirements
Date Tue, 03 Nov 2009 01:27:25 GMT
Ok, my "naive" thinking about FieldCache: for each Term we can quickly
retrieve DocSet. What are memory requirements? Theoretically,
[maxdoc]x[4-bytes DocumentID], plus some (small) array to store terms
pointing to (large) arrays of DocumentIDs.

Mike suggested http://issues.apache.org/jira/browse/LUCENE-1990 to make this
memory requirement even lower... but please correct me if I am wrong with
formula, and I am unsure how it is currently implemented...


Thanks,
Fuad


> -----Original Message-----
> From: Fuad Efendi [mailto:fuad@efendi.ca]
> Sent: November-02-09 8:21 PM
> To: solr-user@lucene.apache.org
> Subject: RE: Lucene FieldCache memory requirements
> 
> Mark,
> 
> I don't understand this:
> > so with a ton of docs and a few uniques, you get a temp boost in the RAM
> > reqs until it sizes it down.
> 
> Sizes down??? Why is it called Cache indeed? And how SOLR uses it if it is
> not cache?
> 
> 
> And this:
> > A pointer for each doc.
> 
> Why can't we use (int) DocumentID? For me, it is natural; 64-bit pointer
to
> an object in RAM is not natural (in Lucene world)...
> 
> 
> So, is it [maxdoc]x[4-bytes], or [maxdoc]x[8-bytes]?...
> -Fuad
> 
> 
> 
> 




Mime
View raw message