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https://issues.apache.org/jira/browse/CALCITE-7906?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Ruben Q L updated CALCITE-7906:
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Description:
LikePattern.likeToRegex turns each % into .* and matches with java.util.regex.
For example, {{%%%%%%%%%%x}} is converted into {{.*.*.*.*.*.*.*.*.*.*x}}, or
{{%a%a%a%a%a%a%a%a%a%a%x}} is converted into
{{.*a.*a.*a.*a.*a.*a.*a.*a.*a.*a.*x}}
A pattern with many wildcards makes the regex engine backtrack heavily when the
name doesn't match.
was:LikePattern.likeToRegex turns each % into .* and matches with
java.util.regex. A pattern with many wildcards makes the regex engine backtrack
heavily when the name doesn't match.
> LikePattern matching time grows exponentially with the number of '%' wildcards
> ------------------------------------------------------------------------------
>
> Key: CALCITE-7906
> URL: https://issues.apache.org/jira/browse/CALCITE-7906
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Reporter: Ruben Q L
> Assignee: Ruben Q L
> Priority: Major
> Labels: pull-request-available
> Fix For: 1.43.0
>
>
> LikePattern.likeToRegex turns each % into .* and matches with
> java.util.regex. For example, {{%%%%%%%%%%x}} is converted into
> {{.*.*.*.*.*.*.*.*.*.*x}}, or {{%a%a%a%a%a%a%a%a%a%a%x}} is converted into
> {{.*a.*a.*a.*a.*a.*a.*a.*a.*a.*a.*x}}
> A pattern with many wildcards makes the regex engine backtrack heavily when
> the name doesn't match.
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