[
https://issues.apache.org/jira/browse/HIVE-25941?focusedWorklogId=724372&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-724372
]
ASF GitHub Bot logged work on HIVE-25941:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 10/Feb/22 09:04
Start Date: 10/Feb/22 09:04
Worklog Time Spent: 10m
Work Description: kasakrisz opened a new pull request #3014:
URL: https://github.com/apache/hive/pull/3014
### What changes were proposed in this pull request?
1. When rewriting queries automatically to use MVs lookup the MVs by the AST
of the subquery should be rewritten.
2. Store MVs AST in `HiveRelOptMaterialization`
3. To get the expanded subquery AST required the lookup generate the
expanded query test only one by using `UnparseTranslator` and
`TokeRewriteStream` and call the parser with the expanded sql query text to get
the AST.
### Why are the changes needed?
`UnparseTranslator` and `TokeRewriteStream` are called for each subquery and
complex queries containing lots of subqueries require more compilation time. By
generating the expanded sql query text of the whole query once and comparing
the ASTs of the subqueries runs faster.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
```
mvn test -Dtest.output.overwrite -DskipSparkTests
-Dtest=TestMiniLlapLocalCliDriver
-Dqfile=materialized_view_rewrite_by_text.q,materialized_view_rewrite_by_text_3.q,materialized_view_rewrite_by_text_4.q,materialized_view_rewrite_by_text_5.q,materialized_view_rewrite_by_text_6.q,materialized_view_rewrite_by_text_7.q,materialized_view_rewrite_by_text_8.q
-pl itests/qtest -Pitests
mvn test -Dtest=TestMaterializedViewsCache -pl ql
```
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Issue Time Tracking
-------------------
Worklog Id: (was: 724372)
Remaining Estimate: 0h
Time Spent: 10m
> Long compilation time of complex query due to analysis for materialized view
> rewrite
> ------------------------------------------------------------------------------------
>
> Key: HIVE-25941
> URL: https://issues.apache.org/jira/browse/HIVE-25941
> Project: Hive
> Issue Type: Bug
> Components: Materialized views
> Reporter: Krisztian Kasa
> Assignee: Krisztian Kasa
> Priority: Major
> Attachments: sample.png
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> When compiling query the optimizer tries to rewrite the query plan or
> subtrees of the plan to use materialized view scans.
> If
> {code}
> set hive.materializedview.rewriting.sql.subquery=false;
> {code}
> the compilation succeed in less then 10 sec otherwise it takes several
> minutes (~ 5min) depending on the hardware.
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