[GitHub] [spark] cloud-fan commented on a change in pull request #31524: [SPARK-34401][SQL][DOCS] Update docs about altering cached tables/views

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cloud-fan commented on a change in pull request #31524:
URL: https://github.com/apache/spark/pull/31524#discussion_r572035577



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File path: docs/sql-ref-syntax-ddl-alter-table.md
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@@ -27,6 +27,9 @@ license: |
 
 `ALTER TABLE RENAME TO` statement changes the table name of an existing table in the database.
 
+If the table is cached, the commands clear cached data of the table and all its dependents that refer to it. The cache will be lazily filled when the next time the table or the dependents are accessed.
+The partition rename command keeps table dependents as cached but the table rename does not. In this way dependents should be re-cached explicitly after table renaming.

Review comment:
       I don't get it. Won't the cache be filled lazily? Why we need to re-cache explicitly?




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