Stamatis Zampetakis created HIVE-23479:
------------------------------------------
Summary: Avoid regenerating JdbcSchema for every table in a query
Key: HIVE-23479
URL: https://issues.apache.org/jira/browse/HIVE-23479
Project: Hive
Issue Type: Improvement
Components: Query Planning
Reporter: Stamatis Zampetakis
Currently {{CalcitePlanner}} generates a complete {{JdbcSchema}} for every
{{JdbcTable}} in the query.
https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/parse/CalcitePlanner.java#L3174
This wastes some resources since every call to {{JdbcSchema#getTable}} needs to
communicate with the database to bring back the tables belonging to the schema.
Moreover, the fact that a schema is created during planning is
counter-intuitive since in principle the schema shouldn't change.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
