tree 71ba36bc6b31365ec143a396a1606e38edd81a27
parent 324c9b939071d39539bf15722855978e753c06c0
author Kaushik Lingarkar <kaushik.lingarkar@linaro.org> 1676494127 -0800
committer Kaushik Lingarkar <kaushik.lingarkar@linaro.org> 1676503076 -0800

Add an analyzer with tokenizer:keyword to prefix fields

Default Elasticsearch analyzer drops square brackets when
performing a query. A keyword tokenizer[1] outputs the
exact same text for queries without dropping any characters.
Also, a keyword tokenizer creates a single term for the given
text which makes 'match_phrase_prefix'[2] searches work as
intended by Gerrit.

For example, consider change C1 with hashtag '[area] subsystem'
and change C2 with 'area subsystem'. A Gerrit query [3] returns
C1 with Lucene and C1,C2 with Elasticsearch (without this change).

This helps match Elasticsearch's behaviour of 'prefixhashtag'
and 'prefixtopic' operators with that of Lucene.

[1] https://www.elastic.co/guide/en/elasticsearch/reference/7.17/analysis-keyword-tokenizer.html
[2] https://www.elastic.co/guide/en/elasticsearch/reference/7.17/query-dsl-match-query-phrase-prefix.html
[3] prefixhashtag:"[area]"

Change-Id: Icf62611af9e8323f98d4cb21d619bf5bc3d73177