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https://issues.apache.org/jira/browse/HIVE-16957?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jesus Camacho Rodriguez updated HIVE-16957:
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Attachment: HIVE-16957.04.patch
> Support CTAS for auto gather column stats
> -----------------------------------------
>
> Key: HIVE-16957
> URL: https://issues.apache.org/jira/browse/HIVE-16957
> Project: Hive
> Issue Type: Sub-task
> Reporter: Pengcheng Xiong
> Assignee: Jesus Camacho Rodriguez
> Priority: Major
> Attachments: HIVE-16957.01.patch, HIVE-16957.02.patch,
> HIVE-16957.03.patch, HIVE-16957.04.patch, HIVE-16957.patch
>
>
> The idea is to rely as much as possible on the logic in
> ColumnStatsSemanticAnalyzer as other operations do. In particular, they
> create a 'analyze table t compute statistics for columns', use
> ColumnStatsSemanticAnalyzer to parse it, and connect resulting plan to
> existing INSERT/INSERT OVERWRITE statement. The challenge for CTAS or CREATE
> MATERIALIZED VIEW is that the table object does not exist yet, hence we
> cannot rely fully on ColumnStatsSemanticAnalyzer.
> Thus, we use same process, but ColumnStatsSemanticAnalyzer produces a
> statement for column stats collection that uses a table values clause instead
> of the original table reference:
> {code}
> select compute_stats(col1), compute_stats(col2), compute_stats(col3)
> from table(values(cast(null as int), cast(null as int), cast(null as
> string))) as t(col1, col2, col3);
> {code}
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