lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jay Yu ...@AI.SRI.COM>
Subject Re: Search for null
Date Tue, 24 Jul 2007 16:40:56 GMT


daniel rosher wrote:
> Perhaps you can use a filter in the following way.
> 
> -Create a filter (via QueryFilter) that would contain all document that
> do not have null values for the field
Interesting: what does the QueryFilter look like? Isn't it just as hard 
as finding out what docs have the null values for the field?
I really like to know your trick here.
> -flip the bits of the filter so that it now contains documents that have
> null values for a field
> -Use the filter in conjunction with subsequent queries.
> 
> This would also help with performance as filters are simply bitsets and
> can cheaply be stored, generated once and used often.
> 
> Dan
> 
> On Mon, 2007-07-23 at 13:57 -0700, Jay Yu wrote:
>> If you want performance, a better way might be to assign some special 
>> string/value (if it's easy to create) to the missing field of docs and 
>> index the field without tokenizing it. Then you may search for that 
>> special value to find the docs.
>>
>> Jay
>>
>> Les Fletcher wrote:
>>> Does this particular range query have any significant performance issues?
>>>
>>> Les
>>>
>>> Erik Hatcher wrote:
>>>> On Jul 23, 2007, at 11:32 AM, testn wrote:
>>>>> Is it possible to search for the document that specified field 
>>>>> doesn't exist
>>>>> or such field value is null?
>>>> This is from Solr, so I'm not sure off the top of my head if this mojo 
>>>> applies by itself, but a search for -fieldname:[* TO *] will result in 
>>>> all documents that do not have the specified field.
>>>>
>>>>     Erik
>>>>
>>>>
>>>> ---------------------------------------------------------------------
>>>> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
>>>> For additional commands, e-mail: java-user-help@lucene.apache.org
>>>>
>>> ---------------------------------------------------------------------
>>> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
>>> For additional commands, e-mail: java-user-help@lucene.apache.org
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
>> For additional commands, e-mail: java-user-help@lucene.apache.org
>>
>>
>>
>> <<This email has been scanned for virus and spam content>>
> Daniel Rosher
> Developer
> 
> 
> d: 0207 3489 912
> t: 0870 2020 121
> f: 0870 2020 131
> m: 
> http://www.hotonline.com/
> 
> 
> 
> 
> 
> 
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - -
> This message is sent in confidence for the addressee only. It may contain privileged

> information. The contents are not to be disclosed to anyone other than the addressee.

> Unauthorised recipients are requested to preserve this confidentiality and to advise

> us of any errors in transmission. Thank you.
> 
> hotonline ltd is registered in England & Wales. Registered office: One Canada Square,

> Canary Wharf, London E14 5AP. Registered No: 1904765.
> 
> 
> This message has been scanned for viruses by BlackSpider MailControl - www.blackspider.com
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
> For additional commands, e-mail: java-user-help@lucene.apache.org
> 

---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org


Mime
View raw message