[ https://issues.apache.org/jira/browse/SPARK-47409?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Wenchen Fan reassigned SPARK-47409: ----------------------------------- Assignee: David Milicevic > StringTrim & StringTrimLeft/Right/Both (binary & lowercase collation only) > -------------------------------------------------------------------------- > > Key: SPARK-47409 > URL: https://issues.apache.org/jira/browse/SPARK-47409 > Project: Spark > Issue Type: Sub-task > Components: SQL > Affects Versions: 4.0.0 > Reporter: Uroš Bojanić > Assignee: David Milicevic > Priority: Major > Labels: pull-request-available > > Enable collation support for the *StringTrim* built-in string function in > Spark (including {*}StringTrimBoth{*}, {*}StringTrimLeft{*}, > {*}StringTrimRight{*}). First confirm what is the expected behaviour for > these functions when given collated strings, and then move on to > implementation and testing. One way to go about this is to consider using > {_}StringSearch{_}, an efficient ICU service for string matching. Implement > the corresponding unit tests (CollationStringExpressionsSuite) and E2E tests > (CollationSuite) to reflect how this function should be used with collation > in SparkSQL, and feel free to use your chosen Spark SQL Editor to experiment > with the existing functions to learn more about how they work. In addition, > look into the possible use-cases and implementation of similar functions > within other other open-source DBMS, such as > [PostgreSQL|[https://www.postgresql.org/docs/]]. > > The goal for this Jira ticket is to implement the *StringTrim* function so it > supports binary & lowercase collation types currently supported in Spark. To > understand what changes were introduced in order to enable full collation > support for other existing functions in Spark, take a look at the Spark PRs > and Jira tickets for completed tasks in this parent (for example: Contains, > StartsWith, EndsWith). > > Read more about ICU [Collation Concepts|http://example.com/] and > [Collator|http://example.com/] class, as well as _StringSearch_ using the > [ICU user > guide|https://unicode-org.github.io/icu/userguide/collation/string-search.html] > and [ICU > docs|https://unicode-org.github.io/icu-docs/apidoc/released/icu4j/com/ibm/icu/text/StringSearch.html]. > Also, refer to the Unicode Technical Standard for string > [searching|https://www.unicode.org/reports/tr10/#Searching] and > [collation|https://www.unicode.org/reports/tr35/tr35-collation.html#Collation_Type_Fallback]. -- This message was sent by Atlassian Jira (v8.20.10#820010) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org