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From "daniel rosher" <daniel.ros...@hotonline.com>
Subject Re: Search for null
Date Tue, 24 Jul 2007 11:48:30 GMT
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
-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
> >>
> >>
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Daniel Rosher
Developer


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