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Apr 16, 2018
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Glossary update, Closes Issue #16891 #29127

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9d28ba1
Glossary update, Closes Issue #16891
refactormyself Mar 17, 2018
d28152e
Updated based on reviews
refactormyself Mar 21, 2018
a14b6c7
Updated based on review comments
refactormyself Mar 28, 2018
6d091ff
"+" used for styling restored and more editing
refactormyself Mar 29, 2018
f57cb47
Reverted some unrelated changes made and added relative link
refactormyself Apr 3, 2018
69a9fc3
changed ` "filter" context ` to ` filter context`
refactormyself Apr 4, 2018
2c40605
Corrected absolute link to the proper relative link
refactormyself Apr 4, 2018
b5024e8
fix bad link syntax
refactormyself Apr 12, 2018
5bc957a
Edit link to query_filter_context, now getting error
refactormyself Apr 13, 2018
3813c91
fix the problem with the link to query-filter-context
refactormyself Apr 14, 2018
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24 changes: 24 additions & 0 deletions docs/reference/glossary.asciidoc
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`object`. The mapping also allows you to define (amongst other things)
how the value for a field should be analyzed.

[[glossary-filter]] filter ::

A filter is a query. It is a kind of query which does not give a score, so it is
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@cbuescher cbuescher Mar 28, 2018

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Maybe you can join the first two sentences to make it more fluent, e.g. "A filter is a <<glossary-query,scoring queries>> that ..." and then join the second sentence.
Maybe use something like "produces a score" or "scores documents" instead of "give a score"?

known as a "non-scoring" query.It is only concerned about answering the question -
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@cbuescher cbuescher Mar 28, 2018

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nit: whitespace between "query.It". Although the difference won't show up in the docs I think, it improves readability here.

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@refactormyself refactormyself Mar 28, 2018

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Thanks, @cbuescher I will work on your review. As a beginner to Elasticsearch myself, I appreciate the importance of getting the glossary right. I'll be happy to get it right.

"Does this document match?". The answer is always a simple, binary yes or no. This kind of query is said to be made
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@cbuescher cbuescher Mar 28, 2018

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Could you wrap this (and the following lines) roughly at the same position as the previous lines? We have different line lengths in the docs throughout the documentation but at least in one paragraph it would be nice if it was roughly similar. Maybe it makes sense to do the wrapping in the end just before the PR is ready to be merged though, to just go through the trouble once.

in a "filtering" context (e.g. Is the created date in the range 2013 - 2014?), hence it is called a filter. Filters are
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@cbuescher cbuescher Mar 28, 2018

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Maybe we should link to https://www.elastic.co/guide/en/elasticsearch/reference/current/query-filter-context.html when mentioning the filter context. Also it would be great if it would be clearer that "filter context" defines specific locations of a query clause in a combination of queries. If this is too much detail for the glossary, I think linking to the "filter context" paragraph and removing the details here is fine as well.

simple checks for set inclusion or exclusion. The goal of filtering is to reduce the
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@cbuescher cbuescher Mar 28, 2018

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"The goal of filtering is to reduce the number of documents"

This might be true most of the time, but e.g. constant_score isn't really about reducing the document set, its just about saying you don't care about the score. I'd be okay with adding "most of the time" somewhere, maybe also leave out the "instead of..." part, since reducing document set size might also happen in scoring queries.

number of documents that have to be examined, instead of what happens in the case of
<<glossary-query,scoring queries>>.
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@cbuescher cbuescher Mar 19, 2018

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I don't undestand the reference to scoring queries in this sentence, maybe you can explain or rephrase to make this clearer?

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@refactormyself refactormyself Mar 21, 2018

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The goal of filtering is to reduce the number of documents that have to be examined, instead of what happens in the case of <<glossary-query,scoring queries>>.

The reference is also meant to provide a link to the reader for comparism


[[glossary-index]] index ::

An index is like a _table_ in a relational database. It has a
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+
See also <<glossary-routing,routing>>

[[glossary-query]] query ::

A query is the basic component of a search. A search can be defined by one or more queries
which can be mixed and matched in endless combinations. The term Query refers to all queries
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@cbuescher cbuescher Mar 28, 2018

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I'd scratch this statement, I think of "Query" as a superset of both "scoring queries" and filters, so I wouldn't introduce a distinction here.

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@refactormyself refactormyself Mar 28, 2018

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Please, I will like to clarify this. So you mean whenever the term Query is used it can either mean "filters" or "scoring queries". So, unless it is clarified it can be either (or I guess, even both).

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@cbuescher cbuescher Mar 28, 2018

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Others might disagree, but my understanding is that we only have "queries" in elasticsearch now (there used to be special filters in earlier versions). Some queries, if used in a "filtering context" as described in the link mentioned above, are also refered to as "filters" or "non-scoring queries" as oposed to "scoring queries" (when the queries are producing scores for documents). Whether something is a filter or not depends on their location. e.g. a term_query is generally speaking alway a query, but when it is used e.g. in a boolean queries filter clause it is also refered to as a filter in our documentation.

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@cbuescher cbuescher Mar 28, 2018

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The above explanation might be a bit verbose for the glossary however, so making it a bit more succinct would be the goal here.

which not only determine if a document matches, but also calculate how well the document matches.
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@cbuescher cbuescher Mar 28, 2018

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Maybe say "Queries that calculate how well the document matches are also known as "scoring queries", as oposed to queries that only determine if a document matches, which are also called <<glossary-filter,filters>>.

This calculation is refered to as scoring, hence these queries are also known as "scoring queries".
A scoring query calculates how relevant each document is to the query, and assigns
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@cbuescher cbuescher Mar 28, 2018

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I would leave out the notion of "relevance" here, this is opening yet another term that we'd need to refine more carefully I think. I would suggest using "how well a document mathces a query", "score" and "sort by score" instead.

it a relevance score, which is later used to sort matching documents by relevance.
This concept of relevance is well suited to full-text search, where there is seldom a
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@cbuescher cbuescher Mar 28, 2018

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Just leave out "concept of relevance" if you agree with my former proposal.

completely “correct” answer. These queries are takes more resources than
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Maybe use "Scoring queries" at the beginning of this sentence here.

<<glossary-filter,non scoring queries>> and their query results are not cacheable.
As a general rule, use query clauses for full-text search or for any condition that should
affect the relevance score, and use filters for everything else.
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@cbuescher cbuescher Mar 28, 2018

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maybe user "condition that requires scoring" if you agree on leaving you the notion of relevance here.


[[glossary-replica-shard]] replica shard ::

Each <<glossary-primary-shard,primary shard>> can have zero or more
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