[CALCITE-1739] backend jdbc connection does not returned to connection pool after execute a query.

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: core

Environment

JDK 8

• Assignee: Unassigned
• Reporter: Jingwu Li
• Created: 03/Apr/17 18:12
• Updated: 19/May/22 02:02

Description

When we use calcite jdbc adapter to connect to backend database like Oracles, after running query, the connection does not get returned to connection pool after execution. The apache jdbc dbcp connection pool default max connection is 8. So after running a couple times of queries, all connections got used, the new request got hang due to not able to get hold of a free connection.

In org.apache.calcite.runtime.ResultSetEnumerable class
line 146 statement = null;
147 connection = null;
should we remove those lines so in the finally block the connection.close(); can be executed?

Issue Links

• is related to: CALCITE-5099 ResultSetEnumerable.enumeratorBasedOnStatement cause the backend connection leak