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https://issues.apache.org/jira/browse/DRILL-5899?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Padma Penumarthy updated DRILL-5899:
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Description:
For the 4 simple patterns we have i.e. startsWith, endsWith, contains and
constant,, we do not need the overhead of charSequenceWrapper. We can work with
DrillBuf directly. This will save us from doing isAscii check and UTF8 decoding
for each row.
UTF-8 encoding ensures that no UTF-8 character is a prefix of any other valid
character. So, instead of decoding varChar from each row we are processing,
encode the patternString once during setup and do raw byte comparison. Instead
of bounds checking and reading one byte at a time, we get the whole buffer in
one shot and use that for comparison.
This improved overall performance for filter operator by around 20%.
was:
For simple pattern matcher, we do not have to do isAscii check.
UTF-8 encoding ensures that no UTF-8 character is a prefix of any other valid
character. So, for the 4 simple patterns we have i.e. startsWith, endsWith,
contains and constant, we can get rid of this check. This will help improve
performance.
> Simple pattern matchers can work with DrillBuf directly
> -------------------------------------------------------
>
> Key: DRILL-5899
> URL: https://issues.apache.org/jira/browse/DRILL-5899
> Project: Apache Drill
> Issue Type: Improvement
> Components: Execution - Flow
> Reporter: Padma Penumarthy
> Assignee: Padma Penumarthy
> Priority: Critical
>
> For the 4 simple patterns we have i.e. startsWith, endsWith, contains and
> constant,, we do not need the overhead of charSequenceWrapper. We can work
> with DrillBuf directly. This will save us from doing isAscii check and UTF8
> decoding for each row.
> UTF-8 encoding ensures that no UTF-8 character is a prefix of any other valid
> character. So, instead of decoding varChar from each row we are processing,
> encode the patternString once during setup and do raw byte comparison.
> Instead of bounds checking and reading one byte at a time, we get the whole
> buffer in one shot and use that for comparison.
> This improved overall performance for filter operator by around 20%.
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