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https://issues.apache.org/jira/browse/IMPALA-3316?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16495177#comment-16495177
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Attila Jeges commented on IMPALA-3316:
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[~boristyukin] The change is under review: https://gerrit.cloudera.org/#/c/9986/
> convert_legacy_hive_parquet_utc_timestamps=true makes reading parquet tables
> 30x slower
> ---------------------------------------------------------------------------------------
>
> Key: IMPALA-3316
> URL: https://issues.apache.org/jira/browse/IMPALA-3316
> Project: IMPALA
> Issue Type: Bug
> Components: Backend
> Affects Versions: impala 2.3
> Environment: CDH 5.5.2/ Impala 2.3
> Parquet table with a timestamp column
> Secure cluster
> convert_legacy_hive_parquet_utc_timestamps=true
> Timestamp column is not being filtered on
> Reporter: Ruslan Dautkhanov
> Assignee: Attila Jeges
> Priority: Minor
> Attachments: screenshot-1.png, screenshot-2.png
>
>
> Enabling convert_legacy_hive_parquet_utc_timestamps=true
> makes simple queries that don't even filter on a timestamp attribute perform
> really poorly.
> Parquet table.
> Impala 2.3 / CDH 5.5.2.
> convert_legacy_hive_parquet_utc_timestamps=true makes following simple query
> 30x slower (1.1minutes -> over 30 minutes).
> {quote} select * from parquet_table_with_a_timestamp_attribute where
> bigint_attribute=1000771658169 {quote}
> Notice I did not even filter on a timestamp attribute.
> Made multiple tests with and without
> convert_legacy_hive_parquet_utc_timestamps=true impalad present.
> Also, from https://issues.cloudera.org/browse/IMPALA-1658
> {quote} Casey Ching added a comment - 15/Jun/15 5:12 PM
> Btw, a perf test showed enabling this flag was 10x slower. {quote}
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