Uwe, thank you very much. This sounds like the pretty best solution!
2012/2/15 Uwe Schindler <u...@thetaphi.de>: > Hi, > > Thanks for explanation. I almost expected that it has to do with" stored > fields". It's easy to fix: > >> ah ok, I know what you mean. We have to read out the stored field values >> later. >> A field can have multiple (stored) values (several >> document.add(fieldable) invocations for one field). Further, we have the >> problem that some field values are logically related to each other. Since >> Lucene has no possibility to define relationships between documents, and >> offer >> e.g. key-based, table-join-similar stuff, we took this approach as a kind of >> approximation: >> >> Example document: (*fieldName: value1, value2, ..) >> * personId: personId1, personId2, personId3, personIdN >> * personName: personName1, personName2, personName3, personNameN >> * personAge: personAge1, personAge2, personAge3, personAgeN >> * tagId: tagId1, tagId2, tagId3, tagIdN >> * tagLabel: tagLabel1, tagLabel2, tagLabel3, tagLabelN >> * >> >> In the case there is e.g. no person age known for person 2, we have to >> insert an >> empty entry to ensure that all data for person 3 is in the third stored >> field value >> in this document: >> >> * personName: personName1, personName2, personName3, personNameN >> * personAge: personAge1, EMPTYENTRY, personAge3, personAgeN >> >> since you can't create a numeric Field instance with a null entry (that >> would be >> wonderfull), we insert a string fieldable, so in this example the values for >> 'personage1, personage3, and personageN are NumericFields, and >> EMPTYENTRY is a standard string field with a zero-length string value "". >> This >> results into exceptions when we sort against the personAge field. > > Then add those zero-length string fields with Field.Index.NO - they dnt have > to be indexed. For your use case Store.YES is enough! > >> We also thinked about NaN or negative infinity as placeholder - but these are >> only available at Float and Double. For Longs and Integers, only min_value >> and >> max_value are offered. Further, we have to convert this value back into null >> or >> something empty, whereby the empty string value field integrates seamless as >> it should (with respect to the exceptions ;) ) But maybe there is no other >> possibility to take the max/min values? >> >> >> >> 2012/2/15 Uwe Schindler <u...@thetaphi.de>: >> > Hi, >> > >> > This looks like an XY problem >> (http://www.perlmonks.org/index.pl?node_id=542341). Maybe you should first >> explain to us, why you need that. In Lucene fields have no "equal length" or >> something like that, especially numeric fields are tokenized and contain of >> several tokens separately indexed. So what do you mean with equal length? >> Why must this "length" be identical? >> > >> > The only suggestion is to index a "fake" placeholder value (like -1, >> > infinity, >> NaN). If you only need it in the "stored" fields, just store it but don't >> index it. >> > >> > Uwe >> > >> > ----- >> > Uwe Schindler >> > H.-H.-Meier-Allee 63, D-28213 Bremen >> > http://www.thetaphi.de >> > eMail: u...@thetaphi.de >> > >> > >> >> -----Original Message----- >> >> From: Christian Reuschling [mailto:christian.reuschl...@gmail.com] >> >> Sent: Wednesday, February 15, 2012 12:58 PM >> >> To: java-user >> >> Subject: Empty numeric field >> >> >> >> Hi all, >> >> >> >> for some reason, we need empty numeric field values (to ensure that >> >> the length of the field value list is constant). We tried to add an >> >> empty String- Fieldable instead in the case a value is not present, >> >> which seemed to work for searching. >> >> Nevertheless, when we want to sort against this field, sadly we fall >> >> into exceptions. >> >> >> >> Is there any possibility to store empty numeric fields into a >> >> document/the index? >> >> >> >> Thanks >> >> >> >> Chris >> >> >> >> --------------------------------------------------------------------- >> >> 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 >> > >> >> --------------------------------------------------------------------- >> 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 > --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
