lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Robert Muir (JIRA)" <>
Subject [jira] Updated: (LUCENE-2529) always apply position increment gap between values
Date Mon, 04 Oct 2010 18:41:38 GMT


Robert Muir updated LUCENE-2529:

    Attachment: LUCENE-2529_test.patch

Here's a patch, showing what i mean about why it is bad to discard the first position.

The test uses SpanFirstQuery (imagine a custom queryparser that supports a "starts-with" operator).

the test passes on trunk, but fails if i apply the patch to discard the position of the first

> always apply position increment gap between values
> --------------------------------------------------
>                 Key: LUCENE-2529
>                 URL:
>             Project: Lucene - Java
>          Issue Type: Bug
>          Components: Index
>    Affects Versions: 2.9.3, 3.0.2, 3.1, 4.0
>         Environment: (I don't know which version to say this affects since it's some
quasi trunk release and the new versioning scheme confuses me.)
>            Reporter: David Smiley
>            Assignee: Koji Sekiguchi
>            Priority: Minor
>             Fix For: 3.1, 4.0
>         Attachments: LUCENE-2529_always_apply_position_increment_gap_between_values.patch,
LUCENE-2529_skip_posIncr_for_1st_token.patch, LUCENE-2529_skip_posIncr_for_1st_token.patch,
>   Original Estimate: 1h
>  Remaining Estimate: 1h
> I'm doing some fancy stuff with span queries that is very sensitive to term positions.
 I discovered that the position increment gap on indexing is only applied between values when
there are existing terms indexed for the document.  I suspect this logic wasn't deliberate,
it's just how its always been for no particular reason.  I think it should always apply the
gap between fields.  Reference line 82:
> if (fieldState.length > 0)
>           fieldState.position += docState.analyzer.getPositionIncrementGap(;
> This is checking fieldState.length.  I think the condition should simply be:  if (i >
> I don't think this change will affect anyone at all but it will certainly help me.  Presently,
I can either change this line in Lucene, or I can put in a hack so that the first value for
the document is some dummy value which is wasteful.

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

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

View raw message