[jira] [Closed] (OAK-9884) Optimization: use Elastic prefix queries instead of wildcard queries for "like foo%" constraints

["Nitin Gupta (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/OAK-9884?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Nitin Gupta closed OAK-9884.
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> Optimization: use  Elastic prefix queries instead of wildcard queries for "like foo%" constraints 
> --------------------------------------------------------------------------------------------------
>
>                 Key: OAK-9884
>                 URL: https://issues.apache.org/jira/browse/OAK-9884
>             Project: Jackrabbit Oak
>          Issue Type: Improvement
>          Components: indexing
>            Reporter: Nuno Santos
>            Priority: Minor
>             Fix For: 1.46.0
>
>
> For a query like
> {noformat}
> select * from [nt:base] where [propa] like '12%'{noformat}
> the Elastic module will generate a wildcard query of the form 
> {noformat}
> {"bool":{"filter":[{"wildcard":{"propa":{"value":"12*"}}}]}}{noformat}
> But the Elastic query can be done more efficiently with
> {noformat}
> {"bool":{"filter":[{"prefix":{"propa":{"value":"12"}}}]}}{noformat}
> That is, any like condition that has a single wilcard of type % at the end, can be rewritten as a prefix query.
> The current code on trunk attempts to implement this optimization, but due to an off-by-one bug, the logic that would use prefix queries is never executed.  
> [https://github.com/apache/jackrabbit-oak/blob/27a7a9ffa0e78e5b258626aef24066eb58efc559/oak-search-elastic/src/main/java/org/apache/jackrabbit/oak/plugins/index/elastic/query/ElasticRequestHandler.java#L750-L771]
> Also see OAK-9881 for a more detailed analysis. 
> h3. Context
> Elastic documentation suggests that wilcard queries are expensive:
> [https://www.elastic.co/guide/en/elasticsearch/reference/7.17/query-dsl-wildcard-query.html]
> h4. Allow expensive queries
> Wildcard queries will not be executed if [{{search.allow_expensive_queries}}|https://www.elastic.co/guide/en/elasticsearch/reference/7.17/query-dsl.html#query-dsl-allow-expensive-queries] is set to false.



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