frange with multi-valued fields

[Russell Black <rb...@fold3.com>]

Has anyone had experience using frange with multi-valued fields?  In solr 3.5 doing so results in the error: "can not use FieldCache on multivalued field"  

Here's the use case.  We have multiple years attached to each document and want to be able to refine by a year range.  We're currently using the standard range query syntax [ 1900 TO 1910 ] which works, but those queries are slower than we would like.  I've seen reports that using frange can greatly improve performance.  http://solr.pl/en/2011/05/30/quick-look-frange/  

>From what I can tell, there seem to be efforts in 4.0 to allow functions to work on multivalued fields.  Does anyone know for sure?

Thanks,

Russ

Re: frange with multi-valued fields

[Chris Hostetter <ho...@fucit.org>]

: Has anyone had experience using frange with multi-valued fields?  In 
: solr 3.5 doing so results in the error: "can not use FieldCache on 
: multivalued field"

correct.

: Here's the use case.  We have multiple years attached to each document 
: and want to be able to refine by a year range.  We're currently using 
: the standard range query syntax [ 1900 TO 1910 ] which works, but those 
: queries are slower than we would like.  I've seen reports that using 
: frange can greatly improve performance.  
: http://solr.pl/en/2011/05/30/quick-look-frange/

note that there is a mistake in the "Faster implementation" 
column of performance table on that article .. the actaul data (and hte 
paragraph after the table) indicate that...

	"standard range query is faster only for queries that cover a
 	small number of terms from the given field." 

Yonik got similar results when he did testing on range queries over 
strings, but the specifics on where the cut-off point was were slightly 
different...

https://yonik.wordpress.com/2009/07/06/ranges-over-functions-in-solr-1-4/

In general you'd have to test it, but for things like "years" 
unless you are dealing really big spans of time (ie: 
[1901 TO 200000]) and will have ranges that are generally large relative 
the total span of data you are dealing with, i seriously  doubt fgrange 
would be much faster for you if you had a single valued fields -- and the 
bottom line is frange won't work with multivalued fields.

forget about frange for a moment, and tell us more about your specific 
sitaution. to start with: what field configuration are you using right now 
for your "year" field? specificly are you using TrieIntField? have you 
tried tunning the options on it? how many unique year values are in your 
corpus? how big to your ranges usually get?



https://people.apache.org/~hossman/#xyproblem
Your question appears to be an "XY Problem" ... that is: you are dealing
with "X", you are assuming "Y" will help you, and you are asking about "Y"
without giving more details about the "X" so that we can understand the
full issue.  Perhaps the best solution doesn't involve "Y" at all?
See Also: http://www.perlmonks.org/index.pl?node_id=542341




-Hoss