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OutOfMemoryExceptions Using Oracle JDBC 10.2 Drivers and Statement Caching Due to PreparedStatement and CallableStatement Holding char[] Buffers (Doc ID 1082118.1)

Last updated on AUGUST 30, 2023

Applies to:

JDBC - Version to [Release 10.2]
Information in this document applies to any platform.


Using JDBC driver in a J2EE application, preparedStatement continuously takes memory from the total heap, causing outofmemory errors.
Looking at the heap dump, the majority seems to be occupied by char[] arrays:

Total heap size: 805,304,832 bytes (almost to the -Xmx value of 768MB)
Total char[] size: 569,319,826 bytes with 638,443 instances.
Total String instances: 636,355

There are about 875 char[] array of 586,376 bytes. All these arrays are coming from "oracle.jdbc.driver.T4CCallableStatement" class instances, with an instance count of 890.

The issue occurs when using Statement Caching.


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