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https://issues.apache.org/jira/browse/HIVE-29235?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18024161#comment-18024161
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Jaeho Yoo edited comment on HIVE-29235 at 10/1/25 11:15 PM:
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[~dkuzmenko]
It's basicStats. It estimates stats in absense of statistics.
[https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/stats/StatsUtils.java#L275]
Also, when in optimizer, when it tries to get row count, it sums up all row
count for each partitions.
https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/optimizer/StatsOptimizer.java#L933-L958
was (Author: jyoo94):
[~dkuzmenko]
It's basicStats. It estimates stats in absense of statistics.
https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/stats/StatsUtils.java#L275
> Iceberg returns incorrect count value
> -------------------------------------
>
> Key: HIVE-29235
> URL: https://issues.apache.org/jira/browse/HIVE-29235
> Project: Hive
> Issue Type: Bug
> Reporter: Jaeho Yoo
> Priority: Major
>
> For iceberg table, Hive tries to read partitionStatistics.
> But if the table doesn't have them, Hive calculates using default statistics,
> which is incorrect.
> We are using Hive 4.1.0.
> SELECT count(*), log_date FROM db1.tbl1 GROUP BY 2;
> +----------+-------------+
> | _c0 | log_date |
> +----------+-------------+
> | 343662 | 2025-09-29 |
> | 2513459 | 2025-09-30 |
>
>
> SELECT count(*) FROM db1.tb1 WHERE log_date = '2025-09-29'; // 2857121
> SELECT count(*) FROM db1.tb1 WHERE log_date = '2025-09-30'; // 2857121
>
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