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From Alexandre Rafalovitch <>
Subject Re: Questions on The Tagger Handler
Date Wed, 01 Aug 2018 14:12:21 GMT
You may find this interesting:
Specifically, slides 15-18.

Basically, it is a reverse from normal search. You are searching for
occurrences of the already indexed terms (here, the place names) in
the text you sent. And it returns information about what it found and
where in your original text it is (the offsets). The text you send to
the tagger does not end up in Solr.

What is missing is a good visualization of what it found. Which would
be a bit like highlighter, taking those offsets and applying them to
the original text.


On 1 August 2018 at 05:59, Zheng Lin Edwin Yeo <> wrote:
> Hi,
> I am trying out the Tagger Handler in Solr 7.4.0 by following the tutorial
> from
> I have managed to set it up to work, but what I do not really understand is
> how to analyse the output. From the example, it seems to be trying to tag
> 'Hello New York City', and it returns one output. This seems more like
> searching for the 'name' field (in the example, the 'name' field is copied
> to the 'name_tag' field for tagging) and getting the records with the name
> "New York City".
> What is the actual purpose of doing this?
> Also, what does the "startOffset" and "endOffset" means, and how the value
> is calculated?
> {
>   "responseHeader":{
>     "status":0,
>     "QTime":1},
>   "tagsCount":1,
>   "tags":[[
>       "startOffset",6,
>       "endOffset",19,
>       "ids",["5128581"]]],
>   "response":{"numFound":1,"start":0,"docs":[
>       {
>         "id":"5128581",
>         "name":["New York City"],
>         "countrycode":["US"]}]
>   }}
> Regards,
> Edwin

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