Hi Uwe, Thanks for clarifying. That makes sense. Thanks, Alex Klibisz On Mon, Jul 5, 2021 at 9:22 AM Uwe Schindler <u...@thetaphi.de> wrote:
> Hi, > > Sorry I misunderstood you question, you want to lookup the UUID in another > system! > Then the approach you are doing is correct. Either store as stored field > or as docvalue. An inverted index cannot store additional data, because it > *is* inverted, it is focused around *terms* not documents. The posting list > of each term can only store internal, numeric lucene doc ids. Those have > then to be used to lookup the actual contents from e.g. stored fields > (possibility A) or DocValues (possibility B). We can't store UUIDs in the > highly compressed posting list. > > Uwe > > ----- > Uwe Schindler > Achterdiek 19, D-28357 Bremen > https://www.thetaphi.de > eMail: u...@thetaphi.de > > > -----Original Message----- > > From: Uwe Schindler <u...@thetaphi.de> > > Sent: Monday, July 5, 2021 3:10 PM > > To: java-user@lucene.apache.org > > Subject: RE: Does Lucene have anything like a covering index as an > alternative > > to DocValues? > > > > You need to index the UUID as a standard indexed StringField. Then you > can do > > a lookup using TermQuery. That's how all systems like Solr or > Elasticsearch > > handle document identifiers. > > > > DocValues are for facetting and sorting, but looking up by ID is a > typical use > > case for an inverted index. If you still need to store it as DocValues > field, just > > add it with both types. > > > > Uwe > > > > ----- > > Uwe Schindler > > Achterdiek 19, D-28357 Bremen > > https://www.thetaphi.de > > eMail: u...@thetaphi.de > > > > > -----Original Message----- > > > From: Alex K <aklib...@gmail.com> > > > Sent: Monday, July 5, 2021 2:30 AM > > > To: java-user@lucene.apache.org > > > Subject: Does Lucene have anything like a covering index as an > alternative to > > > DocValues? > > > > > > Hi all, > > > > > > I am curious if there is anything in Lucene that resembles a covering > index > > > (from the relational database world) as an alternative to DocValues for > > > commonly-accessed values? > > > > > > Consider the following use-case: I'm indexing docs in a Lucene index. > Each > > > doc has some terms, which are not stored. Each doc also has a UUID > > > corresponding to some other system, which is stored using DocValues. > When I > > > run a query, I get back the TopDocs and use the doc ID to fetch the > UUID > > > from DocValues. I know that I will *always* need to go fetch this > UUID. Is > > > there any way to have the UUID stored in the actual index, rather than > > > using DocValues? > > > > > > Thanks in advance for any tips > > > > > > Alex Klibisz > > > > > > --------------------------------------------------------------------- > > 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 > >
