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Posted to issues@spark.apache.org by "Achuth Narayan Rajagopal (JIRA)" <ji...@apache.org> on 2019/05/17 17:22:00 UTC
[jira] [Updated] (SPARK-27679) Improve queries with LIKE expression
[ https://issues.apache.org/jira/browse/SPARK-27679?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Achuth Narayan Rajagopal updated SPARK-27679:
---------------------------------------------
Description:
The following improvements are possible when simplifying {{LIKE}} expressions by adding support for underscore case optimization similar to '%' :
{{ Filter name#10 LIKE _abc → Filter (length(name#10) = 4 && EndsWith(name#10, abc))}}
{{Filter name#10 LIKE abc_ → Filter (length(name#10) = 4 && StartsWith(name#10, abc))}}
{{Filter name#10 LIKE abc_def -> Filter ((length(name#10) = 7) && (StartsWith(name#10, abc) && EndsWith(name#10, def))) }}
was:
The following improvements are possible when simplifying `LIKE` expressions -
# In the case where pattern is `null` replace like expression with Literal(`false`), so in cases where applicable we can replace the underlying relation with `LocalRelation <empty>`.
# Add support for underscore case optimization similar to '%'.
> Improve queries with LIKE expression
> ------------------------------------
>
> Key: SPARK-27679
> URL: https://issues.apache.org/jira/browse/SPARK-27679
> Project: Spark
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 2.4.3
> Reporter: Achuth Narayan Rajagopal
> Priority: Major
>
> The following improvements are possible when simplifying {{LIKE}} expressions by adding support for underscore case optimization similar to '%' :
> {{ Filter name#10 LIKE _abc → Filter (length(name#10) = 4 && EndsWith(name#10, abc))}}
> {{Filter name#10 LIKE abc_ → Filter (length(name#10) = 4 && StartsWith(name#10, abc))}}
> {{Filter name#10 LIKE abc_def -> Filter ((length(name#10) = 7) && (StartsWith(name#10, abc) && EndsWith(name#10, def))) }}
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