Hi, It looks like you are fetching the stored fields of *all* search results. In general, Lucene is made to return the most relevant documents to the user. Fetching stored fields is then done only for like the 10 top-ranking results. If you do this for all results (which can be thousands), this is of course a performance problem: the stored fields are compressed on disk and after decompression the bytes have to be converted to UTF-16 Java Strings. There is not much, Lucene can do.
If you use stored fields for ranking purposes (inside function queries), you should change them to numeric docvalues fields. Uwe ----- Uwe Schindler H.-H.-Meier-Allee 63, D-28213 Bremen http://www.thetaphi.de eMail: u...@thetaphi.de > -----Original Message----- > From: Sascha Janz [mailto:sascha.j...@gmx.net] > Sent: Wednesday, August 06, 2014 10:27 AM > To: java-user@lucene.apache.org > Subject: Aw: Re: Performance StringCoding.decode > > i used JMC ( Java Mission Control) from jdk7 u40+ > > > see here > > > http://www.oracle.com/technetwork/java/javase/2col/jmc-relnotes- > 2004763.html > > > > Gesendet: Dienstag, 05. August 2014 um 17:41 Uhr > Von: "d...@neusoft.com" <d...@neusoft.com> > An: "java-user@lucene.apache.org" <java-user@lucene.apache.org> > Betreff: Re: Performance StringCoding.decode how to monitor? use jprofile? > > > > > > From: Sascha Janz > Date: 2014-08-05 22:36 > To: java-user@lucene.apache.org > Subject: Performance StringCoding.decode hi, > > i want to speed up our search performance. so i run test and monitor them > with java mission control. > > the analysis showed that one hotspot is > > > sun.nio.cs.UTF_8$Decoder.decode(byte[], int, int, char[]) > - java.lang.StringCoding.decode(Charset, byte[], int, int) > - java.lang.String.<init>(byte[], int, int, Charset) - > org.apache.lucene.codecs.compressing.CompressingStoredFieldsReader.rea > dField(DataInput, > StoredFieldVisitor, FieldInfo, int) > - > org.apache.lucene.codecs.compressing.CompressingStoredFieldsReader.visi > tDocument(int, > StoredFieldVisitor) > -org.apache.lucene.index.SegmentReader.document(int, StoredFieldVisitor) > -org.apache.lucene.index.IndexReader.document(int, Set) > > we use jdk 1.7.55 and lucene 4.9.0. > > is there a chance to speed this up? or do some changes in lucene > IndexWriterConfig, e.g. use an other codec? > > we use the default values of IndexWriterConfig > > > regards > sascha > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org > > ---------------------------------------------------------------------------------------------- > ----- > Confidentiality Notice: The information contained in this e-mail and any > accompanying attachment(s) is intended only for the use of the intended > recipient and may be confidential and/or privileged of Neusoft Corporation, > its subsidiaries and/or its affiliates. If any reader of this communication > is not > the intended recipient, unauthorized use, forwarding, printing, storing, > disclosure or copying is strictly prohibited, and may be unlawful.If you have > received this communication in error,please immediately notify the sender > by return e-mail, and delete the original message and all copies from your > system. Thank you. > ---------------------------------------------------------------------------------------------- > ----- > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
