Mailing-List: contact solr-dev-help@lucene.apache.org; run by ezmlm
Precedence: bulk
Reply-To: solr-dev@lucene.apache.org
Message-ID: <665635222.1261490909608.JavaMail.jira@brutus>
Date: Tue, 22 Dec 2009 14:08:29 +0000 (UTC)
From: "Yonik Seeley (JIRA)" <jira@apache.org>
To: solr-dev@lucene.apache.org
Subject: [jira] Commented: (SOLR-236) Field collapsing
In-Reply-To: <19014374.1178921656142.JavaMail.jira@brutus>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable


    [ https://issues.apache.org/jira/browse/SOLR-236?page=3Dcom.atlassian.j=
ira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=3D127936=
21#action_12793621 ]=20

Yonik Seeley commented on SOLR-236:
-----------------------------------

bq. As far as I understand from your collapse algorithm proposal, in order =
to save memory you'd like to restrict the group creation to only those that=
 belong in the requested results page.

A ton of memory, and probably a good amount of time too.  It may be the onl=
y variant that certain people would be able to use (but note that it is jus=
t a variant - I'm not proposing doing away with the other options).

bq. I think there might be a problem with pagination as well

Yes, pagination is a sticky issue... but I don't think this algorithm messe=
s it up further.

If we are returning a number of documents (as opposed to a number of groups=
) to the user, how do they avoid splitting on a page in the middle of the g=
roup?  I guess they over-request a little.  What if they want a fixed numbe=
r of groups?  I guess they over-request by a lot (nGroups*collapse.threshol=
d).  Then they need to keep track of how many documents they actually used.

The only thing this algorithm can't do (related to pagination) is give the =
total number of documents after collapsing (and hence can't calculate the e=
xact number of pages).  This can be fine in many circumstances as long as t=
he gui handles it (people don't seem to mind google doing it... I just trie=
d it.  Google didn't show the result count right unless displaying the last=
 page).

> Field collapsing
> ----------------
>
>                 Key: SOLR-236
>                 URL: https://issues.apache.org/jira/browse/SOLR-236
>             Project: Solr
>          Issue Type: New Feature
>          Components: search
>    Affects Versions: 1.3
>            Reporter: Emmanuel Keller
>            Assignee: Shalin Shekhar Mangar
>             Fix For: 1.5
>
>         Attachments: collapsing-patch-to-1.3.0-dieter.patch, collapsing-p=
atch-to-1.3.0-ivan.patch, collapsing-patch-to-1.3.0-ivan_2.patch, collapsin=
g-patch-to-1.3.0-ivan_3.patch, field-collapse-3.patch, field-collapse-4-wit=
h-solrj.patch, field-collapse-5.patch, field-collapse-5.patch, field-collap=
se-5.patch, field-collapse-5.patch, field-collapse-5.patch, field-collapse-=
5.patch, field-collapse-5.patch, field-collapse-5.patch, field-collapse-5.p=
atch, field-collapse-5.patch, field-collapse-5.patch, field-collapse-5.patc=
h, field-collapse-5.patch, field-collapse-5.patch, field-collapse-5.patch, =
field-collapse-solr-236-2.patch, field-collapse-solr-236.patch, field-colla=
psing-extended-592129.patch, field_collapsing_1.1.0.patch, field_collapsing=
_1.3.patch, field_collapsing_dsteigerwald.diff, field_collapsing_dsteigerwa=
ld.diff, field_collapsing_dsteigerwald.diff, quasidistributed.additional.pa=
tch, SOLR-236-FieldCollapsing.patch, SOLR-236-FieldCollapsing.patch, SOLR-2=
36-FieldCollapsing.patch, SOLR-236.patch, SOLR-236.patch, SOLR-236.patch, s=
olr-236.patch, SOLR-236_collapsing.patch, SOLR-236_collapsing.patch
>
>
> This patch include a new feature called "Field collapsing".
> "Used in order to collapse a group of results with similar value for a gi=
ven field to a single entry in the result set. Site collapsing is a special=
 case of this, where all results for a given web site is collapsed into one=
 or two entries in the result set, typically with an associated "more docum=
ents from this site" link. See also Duplicate detection."
> http://www.fastsearch.com/glossary.aspx?m=3D48&amid=3D299
> The implementation add 3 new query parameters (SolrParams):
> "collapse.field" to choose the field used to group results
> "collapse.type" normal (default value) or adjacent
> "collapse.max" to select how many continuous results are allowed before c=
ollapsing
> TODO (in progress):
> - More documentation (on source code)
> - Test cases
> Two patches:
> - "field_collapsing.patch" for current development version
> - "field_collapsing_1.1.0.patch" for Solr-1.1.0
> P.S.: Feedback and misspelling correction are welcome ;-)

--=20
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.