In solr/trunk, we could do this with a pseudo field/transformer:
https://svn.apache.org/repos/asf/lucene/dev/trunk/solr/core/src/java/org/apache/solr/response/transform/

In trunk, you can return a function value -- but i'm not sure what the
syntax for the 'fieldvalue' function would be.  To use other
functions, you just put it in the list:
 &fl=name,id,ord(id)





On Wed, Sep 7, 2011 at 9:01 AM, Erick Erickson <[email protected]> wrote:
> I'm more throwing this out there for discussion rather than implementing
> it. Frankly, I suspect there are better things to spend time on....
>
> Erick
>
> On Wed, Sep 7, 2011 at 7:13 AM, Chris Male <[email protected]> wrote:
>> Hi,
>> You can use the FieldCache to pull the single value of a field for a given
>> document ID.
>> I'm unsure about whether what you're suggesting is a good idea, but it would
>> need to be a custom extension to how fields are retrieved currently.
>>  IndexReader.document(int) visits fields which are stored and the separation
>> between indexed and stored fields is going to grow stronger.
>> Good luck with it though, I can sort of see where you're coming from.
>>
>> On Wed, Sep 7, 2011 at 10:57 PM, Erick Erickson <[email protected]>
>> wrote:
>>>
>>> I'm wondering if there's any utility in returning the first term of an
>>> un-stored but
>>> indexed field. It wouldn't be much use in a field  that broke the
>>> input stream up,
>>> but what about a "string" type? Or something with KeywordTokenizer?
>>>
>>> We could save some index storage space, maybe speed up things a bit.
>>>
>>> Especially in a "string" type, there's no difference between the indexed
>>> term
>>> and the stored term, so why use both?
>>>
>>> My original notion was to let users include an indexed-but-not-stored
>>> field in the fl list, and leave up to them to use it wisely. When
>>> specified, the behavior
>>> would be "return the first term encountered in an
>>> indexed-but-not-tokenized field with
>>> no guarantees". But it also occurs to me that we could do this
>>> automagically for
>>> "string" types.
>>>
>>> I haven't thought this through much, for instance what about
>>> specifying fl=*? And
>>> this changes current programs, users who already (by mistake probably)
>>> specify
>>> unstored fields in to be returned would start seeing new data. I'm sure
>>> there are other gremlins. Not to mention trying to explain it.
>>>
>>> And,  in truth, this really feels like one of those
>>> possible-but-not-worth-the-effort
>>> ideas. But it was in my head when I woke up this morning and I thought I'd
>>> toss
>>> it out there.
>>>
>>> Erick
>>>
>>> ---------------------------------------------------------------------
>>> To unsubscribe, e-mail: [email protected]
>>> For additional commands, e-mail: [email protected]
>>>
>>
>>
>>
>> --
>> Chris Male | Software Developer | JTeam BV.| www.jteam.nl
>>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: [email protected]
> For additional commands, e-mail: [email protected]
>
>

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to