Thanks Uwe, The information you provided is very informative. Two more questions/comments,
- For stored field, it means its original information/structure is kept for search results (I think for an indexed field it means means lost its original form to indexed form), correct? - What means "phonetic fields", "phonetic serach" and "phonetic filter"? Appreciate if you could show an example? regards, Lin On Sat, Jan 26, 2013 at 2:16 PM, Uwe Schindler <u...@thetaphi.de> wrote: > Because you can search on it? The stored fields are only those that should > be displayed to the user with search results. Imagine e.g. Google: Google > displays in its search results the title of the document and some > "description", but it does not display the whole document text. So in their > case, they would "store" the title and some description of every document. > On the other hand you can search on the whole document, so the whole > document text, which could be megabytes of text data (like books), is > "indexed". Other cases where you have indexed-only field that are not > stored are: > - phonetic fields: Often, some fields are indexed a second time as a > duplicate, but with a phonetic filter assigned (that converts all tokens to > phonetic representations). You can then do a phonetic serach in addition to > the exact matching search, but it makes absolutely no sense to "store" the > field 2 times. > - fields only used for faceting or sorting > - ...and many more > > "stored fields" are for display to the user, "indexed fields" are for > retrieval. They have nothing to do with each other. > > Uwe > > ----- > Uwe Schindler > H.-H.-Meier-Allee 63, D-28213 Bremen > http://www.thetaphi.de > eMail: u...@thetaphi.de > > > > -----Original Message----- > > From: Lin Ma [mailto:lin...@gmail.com] > > Sent: Saturday, January 26, 2013 6:01 AM > > To: java-user@lucene.apache.org; ian....@gmail.com > > Subject: Re: about isStored method > > > > Thanks Ian, > > > > If the value is not stored in index, it cannot be retrieved on search > results? > > My confusion is, if a field will not be in search result (isStored == > false), why > > we need such field in Document? > > > > regards, > > Lin > > > > On Sat, Jan 26, 2013 at 4:37 AM, Ian Lea <ian....@gmail.com> wrote: > > > > > If you're new to lucene why are you using such an old version? Stored > > > means the value is stored in the index and can be retrieved later e.g. > > > for displaying on a search results page. Not stored means it isn't and > > > can't be. > > > > > > There was a similar question not long ago on this list - check the > > > archives. > > > > > > And read Lucene In Action. > > > > > > > > > -- > > > Ian. > > > > > > > > > On Fri, Jan 25, 2013 at 4:58 PM, Lin Ma <lin...@gmail.com> wrote: > > > > Hi guys, > > > > > > > > I am new to Lucene and for isStored method for interface Fieldable ( > > > > > > > > > http://lucene.apache.org/core/old_versioned_docs/versions/3_0_3/api/co > > > re/index.html > > > ), > > > > what are the logical meanings for stored and not stored? It is > > > > appreciate if anyone could show me an example. I searched many > > > > tutorials but not > > > found > > > > description for what means stored and what means not stored. > > > > > > > > thanks in advance, > > > > Lin > > > > > > --------------------------------------------------------------------- > > > 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 > >
