[jira] [Created] (TRAFODION-2321) Fix other issues related to statement reuse and Hive tables in CSEs

["Hans Zeller (JIRA)" <ji...@apache.org>]

Hans Zeller created TRAFODION-2321:
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             Summary: Fix other issues related to statement reuse and Hive tables in CSEs
                 Key: TRAFODION-2321
                 URL: https://issues.apache.org/jira/browse/TRAFODION-2321
             Project: Apache Trafodion
          Issue Type: Sub-task
          Components: sql-general
            Reporter: Hans Zeller
            Assignee: Hans Zeller


Besides the security issue, there are a few more problems with using Hive tables to materialize common subexpressions:

- Query caching has to be disabled, since we drop the table as a query ends, but a cached query would reference the same dropped table.

- Executor frees resources of a prepared statement, which drops the table. Then the client executes this statement again.

- Issue with query caching and running two queries with identical plans at the same time. They would conflict in the same table.

Dave Birdsall suggested a solution in a comment in PR772: Create a Hive table at runtime for each statement and bind the name of it at runtime as well. This approach would fix all of the issues listed here.



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