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https://issues.apache.org/jira/browse/HIVE-25867?focusedWorklogId=745642&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-745642
]
ASF GitHub Bot logged work on HIVE-25867:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 22/Mar/22 08:15
Start Date: 22/Mar/22 08:15
Worklog Time Spent: 10m
Work Description: pvary commented on pull request #2947:
URL: https://github.com/apache/hive/pull/2947#issuecomment-1074862624
Thanks for the explanation @zzzzming95! This was a misunderstanding on my
side.
What happens if your query is like this - would the filtering work in this
case?
```
select * from src_play_day WHERE dt='20211125' AND
u_gtype='activity_workshop' limit 10;
```
Notice that I used `'`-s to convert 20211125 to string.
Another question is, how does this work with the other supported backend
databases.
The issue with directSql is that we have to handle the differences between
the SQL engines ourselves.
Also what happens when we have different types, like timestamp/binary/struct?
Thanks for investigating this issue, and coming up with possible solutions!
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Issue Time Tracking
-------------------
Worklog Id: (was: 745642)
Time Spent: 1h 50m (was: 1h 40m)
> Partition filter condition should pushed down to metastore query if it is
> equivalence Predicate
> -----------------------------------------------------------------------------------------------
>
> Key: HIVE-25867
> URL: https://issues.apache.org/jira/browse/HIVE-25867
> Project: Hive
> Issue Type: Improvement
> Components: Standalone Metastore
> Reporter: shezm
> Assignee: shezm
> Priority: Major
> Labels: pull-request-available
> Fix For: 4.0.0
>
> Time Spent: 1h 50m
> Remaining Estimate: 0h
>
> The colnum type of the partition is different from the column type of the hql
> query, the metastore will not push down the query to the RDBMS, but will
> instead get all PARTITIONS.PART_NAME of the hive table then filter it
> according to the hql Expression.
> https://github.com/apache/hive/blob/5b112aa6dcc4e374c0a7c2b24042f24ae6815da1/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/MetaStoreDirectSql.java#L1316
> If the hive table has too many partitions and there are multiple hql queries
> at the same time,RDBMS will increasing CPU IO_WAIT and affect performance.
> If the partition filter condition in hql is an equivalent predicate, the
> metastore should be pushed down to RDBMS, which can optimize the query
> performance of hive large tables.
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