On Thu, Dec 1, 2011 at 7:36 AM, Zhang, Lisheng <lisheng.zh...@broadvision.com> wrote: > Hi Simon, > > Sorry I found that I cannot use payload for this purpose because payload > can be accessed only through term positions but we did not use timestamp > for query. Ideally it would be great if we can have some doc-level "payload" > accessible through docId?
lucene 4 has a feature called IndexDocValues which is essentially a payload per document per field. you can read about it here: http://www.searchworkings.org/blog/-/blogs/introducing-lucene-index-doc-values http://www.searchworkings.org/blog/-/blogs/apache-lucene-flexiblescoring-with-indexdocvalues http://www.searchworkings.org/blog/-/blogs/indexdocvalues-their-applications > > Then your initial suggestion to use CustomScoreQuery would be our solution, > from source code I see sort is implemented by FieldCache and its performance > seems OK even though we didnot cache reader. So we will use CustomeScoreQuery > without cache for now (cutting time stamp to hour or day may help), if too > slow we may consider selected cache. what do you mean by cache readers? simon > > Thanks very much for all your great helps, please point out if you see wrong > in above statements? > > Best regards, Lisheng > > -----Original Message----- > From: Zhang, Lisheng [mailto:lisheng.zh...@broadvision.com] > Sent: Wednesday, November 30, 2011 1:40 PM > To: java-user@lucene.apache.org; simon.willna...@gmail.com > Subject: RE: Boost more recent document > > > Hi, > > Thanks for the very interesting idea! > > Currently we use lucene 2.3.2 and we just use default merge policy (at > any time we have a few segments and after some accumulation small segments > are merged into big ones). I need to double check if docId can reflect doc > age. > > But I have one concern: docId may not reflect true age interval, like docId > difference by 2 may reflect 2m or 1h. If no better choice I may just use > payload and adapt a few query classes? > > Thanks very much for helps, Lisheng > > -----Original Message----- > From: Simon Willnauer [mailto:simon.willna...@googlemail.com] > Sent: Wednesday, November 30, 2011 1:02 PM > To: java-user@lucene.apache.org > Subject: Re: Boost more recent document > > > If you use LogMergePolicy ie. do merges in order you could use the > absolute docID as a relative age value. Smaller docIDs mean younger > documents. Maybe this works for you? > > simon > > On Wed, Nov 30, 2011 at 9:08 PM, Zhang, Lisheng > <lisheng.zh...@broadvision.com> wrote: >> Thanks very much for your helps! I got the point, only problem is that >> I cannot afford to to use FieldCache because in our app we have many >> lucene index data folders, is there another simple way? >> >> Thanks again, Lisheng >> >> -----Original Message----- >> From: Simon Willnauer [mailto:simon.willna...@googlemail.com] >> Sent: Wednesday, November 30, 2011 11:40 AM >> To: java-user@lucene.apache.org >> Subject: Re: Boost more recent document >> >> >> On Wed, Nov 30, 2011 at 6:59 PM, Zhang, Lisheng >> <lisheng.zh...@broadvision.com> wrote: >>> Hi, >>> >>> We need to boost document which is more recent (each doc has time stamp >>> attribute). It seems that >>> we cannot use doc boost at index time because it will be condensed into one >>> byte (cannot differentiate >>> 365 days), so we may use payload (save time stamp as payload) to boost at >>> search time. >>> >>> In our app we let user enter query at browser and use QueryParser to >>> generate query, the query can >>> be different types (TermQuery, BooleanQuery, WildcardQuery, ...), then it >>> seems we need to create >>> each customized query class similar to PayloadTermQuery, is there another >>> simpler way? >> >> you can simply index your timestamp (untokenzied) and wrap your query >> in a CustomScoreQuery. This query accepts your user query and a >> ValueSource. During search CustomScoreQuery calls your valuesource for >> each document that the user query scores and multiplies the result of >> the ValueSource into the score. Inside your valuesource you can simply >> get the timestamps from the FieldCache and calculate your custom >> boost... >> >> hope that helps >> >> simon >>> >>> Thanks very much for helps, Lisheng >> >> --------------------------------------------------------------------- >> 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
