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From Tomislav Poljak <tpol...@gmail.com>
Subject RE: NumericField indexing performance
Date Thu, 15 Apr 2010 11:41:02 GMT
Hi Uwe,
thank you very much for your answers. I've done Document and
NumericField reuse like this:

Document doc = getDocument();
NumericField dateField = new NumericField("date");

for each doc:

doc.add(dateField.setLongValue(Long.parseLong(DateTools.dateToString(date), DateTools.Resolution.MINUTE))));

,but changing it to:

Document doc = getDocument();
NumericField dateField = new NumericField("date");
doc.add(dateField);

for each doc:

dateField.setLongValue(Long.parseLong(DateTools.dateToString(date),
DateTools.Resolution.MINUTE)));

did the trick. Now indexing with NumericField takes minutes, not hours.

Thanks again,

Tomislav





On Wed, 2010-04-14 at 23:38 +0200, Uwe Schindler wrote:
> One addition:
> If you are indexing millions of numeric fields, you should also try to reuse NumericField
and Document instances (as described in JavaDocs). NumericField creates internally a NumericTokenStream
and lots of small objects (attributes), so GC cost may be high. This is just another idea.
> 
> Uwe
> 
> -----
> Uwe Schindler
> H.-H.-Meier-Allee 63, D-28213 Bremen
> http://www.thetaphi.de
> eMail: uwe@thetaphi.de
> 
> 
> > -----Original Message-----
> > From: Uwe Schindler [mailto:uwe@thetaphi.de]
> > Sent: Wednesday, April 14, 2010 11:28 PM
> > To: java-user@lucene.apache.org
> > Subject: RE: NumericField indexing performance
> > 
> > Hi Tomislav,
> > 
> > indexing with NumericField takes longer (at least for the default
> > precision step of 4, which means out of 32 bit integers make 8 subterms
> > with each 4 bits of the value). So you produce 8 times more terms
> > during indexing that must be handled by the indexer. If you have lots
> > of documents, with distinct values the term index gets larger and
> > larger, but search performance increases dramatically (for
> > NumericRangeQueries). So if you index *only* numeric fields and nothing
> > else, a 8 times slower indexing can be true.
> > 
> > If you are not using NumericRangeQuery or you want tune indexing
> > performance, try larger precision Steps like 6 or 8. If you don’t use
> > NumericRangeQuery and only want to index the numeric terms as *one*
> > term, use precStep=Integer.MAX_VALUE. Also check your memory
> > requirements, as the indexer may need more memory and GC costs too
> > much. Also the index size will increase, so lots of more I/O is done.
> > Without more details I cannot say anything about your configuration. So
> > please tell us, how many documents, how many fields and how many
> > numeric fields in which configuration do you use?
> > 
> > Uwe
> > 
> > -----
> > Uwe Schindler
> > H.-H.-Meier-Allee 63, D-28213 Bremen
> > http://www.thetaphi.de
> > eMail: uwe@thetaphi.de
> > 
> > 
> > > -----Original Message-----
> > > From: Tomislav Poljak [mailto:tpoljak@gmail.com]
> > > Sent: Wednesday, April 14, 2010 8:13 PM
> > > To: java-user@lucene.apache.org
> > > Subject: NumericField indexing performance
> > >
> > > Hi,
> > > is it normal for indexing time to increase up to 10 times after
> > > introducing NumericField instead of Field (for two fields)?
> > >
> > > I've changed two date fields from String representation (Field) to
> > > NumericField, now it is:
> > >
> > > doc.add(new NumericField("time").setIntValue(date.getTime()/24/3600))
> > >
> > > and after this change indexing took 10x more time (before it was few
> > > minutes and after more than an hour and half). I've tested with a
> > > simple
> > > counter like this:
> > >
> > > doc.add(new NumericField("endTime").setIntValue(count++))
> > >
> > > but nothing changed, it still takes around 10x longer. If I comment
> > > adding one numeric field to index time drops significantly and if I
> > > comment both fields indexing takes only few minutes again.
> > >
> > > Tomislav
> > >
> > >
> > > ---------------------------------------------------------------------
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> > > For additional commands, e-mail: java-user-help@lucene.apache.org
> > 
> > 
> > 
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> 
> 
> 
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