Re: issues with spellcheck.maxCollationTries and spellcheck.collateExtendedResults

[Jack Krupansky]

Do single-word queries return hits?

Is this a multi-shard environment? Does the request list all the shards 
needed to give hits for all the collations you expect? Maybe the queries are 
being done locally and don't have hits for the collations locally.

-- Jack Krupansky

-----Original Message----- 
From: Markus Jelsma
Sent: Wednesday, June 06, 2012 6:21 AM
To: solr-user@lucene.apache.org
Subject: issues with spellcheck.maxCollationTries and 
spellcheck.collateExtendedResults

Hi,

We've had some issues with a bad zero-hits collation being returned for a 
two word query where one word was only one edit away from the required 
collation. With spellcheck.maxCollations to a reasonable number we saw the 
various suggestions without the required collation. We decreased 
thresholdTokenFrequency to make it appear in the list of collations. 
However, with collateExtendedResults=true the hits field for each collation 
was zero, which is incorrect.

Required collation=huub stapel (two hits) and q=huup stapel

     "collation":{
       "collationQuery":"heup stapel",
       "hits":0,
       "misspellingsAndCorrections":{
         "huup":"heup"}},
     "collation":{
       "collationQuery":"hugo stapel",
       "hits":0,
       "misspellingsAndCorrections":{
         "huup":"hugo"}},
     "collation":{
       "collationQuery":"hulp stapel",
       "hits":0,
       "misspellingsAndCorrections":{
         "huup":"hulp"}},
     "collation":{
       "collationQuery":"hup stapel",
       "hits":0,
       "misspellingsAndCorrections":{
         "huup":"hup"}},
     "collation":{
       "collationQuery":"huub stapel",
       "hits":0,
       "misspellingsAndCorrections":{
         "huup":"huub"}},
     "collation":{
       "collationQuery":"huur stapel",
       "hits":0,
       "misspellingsAndCorrections":{
         "huup":"huur"}}}}}

Now, with maxCollationTries set to 3 or higher we finally get the required 
collation and the only collation able to return results. How can we 
determine the best value for maxCollationTries regarding the decrease of the 
thresholdTokenFrequency? Why is hits always zero?

This is with a today's build and distributed search enabled.

Thanks,
Markus