lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Uwe Schindler" <>
Subject RE: Testing whether a document is up-to-date in Lucene 4.0
Date Fri, 12 Oct 2012 14:23:12 GMT
Maybe also read:
A simple idea would be to wrap the NRT reader by SlowCompositeReaderWrapper, which has DocsEnum.
If you don't do this for searching, the slowness does not matter.


Uwe Schindler
H.-H.-Meier-Allee 63, D-28213 Bremen

> -----Original Message-----
> From: Arjen van der Meijden []
> Sent: Friday, October 12, 2012 4:04 PM
> To:
> Subject: Testing whether a document is up-to-date in Lucene 4.0
> Hello List,
> I'm currently trying to update my Lucene 3.6-application to 4.0.
> Most of it works (although your migration guide lacks a bit of aspects I had to
> figure out myself), but for one fairly large database I want to check whether
> the Document in the Lucene database is already at the latest modification time.
> If so, I can continue to the next item on the list.
> So to do that, I index an additional field in the Document with the modification
> time and later retrieve that.
> With 3.6, I did this:
> IndexReader reader = writer.getReader(); Term idTerm = new Term("idField,
> "idText"); TermDocs termDocs = reader.termDocs(idTerm);
> if(
> {
>   int docNum = termDocs.doc();
>   Document doc = reader.document(docNum);
>   // etc
> }
> It worked as far as I can tell, besides, it worked regardless of whether the
> writer was actually started with a empty directory (on disk) or one that had
> data in it.
> What is the correct way to implement something like the above procedure in
> 4.0? The writer doesn't have a getReader() anymore and the IndexReader
> doesn't have a termDocs()-method (and the docsEnum is only on specific
> IndexReader's?).
> The "migration guide" isn't very clear on this and I wasn't really able to find any
> useful documentation on how the new reader/writer-stuff is actually to be
> used... Did I overlook the documentation?
> And there are some additional things to consider, like the database may not
> have been created yet (i.e. it may be empty at the moment of the above code).
> And in my current code, I only have access to the IndexWriter, a reader or
> searcher hasn't even been created yet.
> Best regards,
> Arjen
> ---------------------------------------------------------------------
> To unsubscribe, e-mail:
> For additional commands, e-mail:

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message