[ http://issues.apache.org/jira/browse/DERBY-210?page=comments#action_12367235 ]
Kathey Marsden commented on DERBY-210: -------------------------------------- There was a separate thread on this issue on the list where concerns were voiced about doing the result set cleanup work in finalize and maybe creating another thread to do that. I talked with Deepa a bit on IRC about the impact of submitting her patch as is without the result set cleanup. The summary is. Before Deepa's patch 4: - No statements or result sets get cleaned up until the end of the connection unless explicitly closed After Deepa's patch 4: - No statements or result sets get cleaned up until the end of the connection unless explicitly closed. After Deepa's planned patch 5: Most statements and result sets get cleaned up automatically. So, I am of the opinion that Deepa's patch can go in as is and another Jira entry filed for the result set cleanup. Her planned work is a huge improvement over the current state. She does not need to include the result set cleanup in her patch for DERBY-210 > Network Server will leak prepared statements if not explicitly closed by the > user until the connection is closed > ---------------------------------------------------------------------------------------------------------------- > > Key: DERBY-210 > URL: http://issues.apache.org/jira/browse/DERBY-210 > Project: Derby > Type: Bug > Components: Network Client > Reporter: Kathey Marsden > Assignee: Deepa Remesh > Attachments: DOTS_ATCJ2_Derby-noPatch.png, DOTS_ATCJ2_Derby-withPatch.png, > derby-210-patch1.diff, derby-210-patch2.diff, derby-210-patch2.status, > derby-210-patch3.diff, derby-210-patch4-v2.diff, derby-210-patch4-v2.status, > derby-210-v2-draft.diff, derby-210-v2-draft.status, derbyStress.java > > Network server will not garbage collect prepared statements that are not > explicitly closed by the user. So a loop like this will leak. > ... > PreparedStatement ps; > for (int i = 0 ; i < numPs; i++) > { > ps = conn.prepareStatement(selTabSql); > rs =ps.executeQuery(); > while (rs.next()) > { > rs.getString(1); > } > rs.close(); > // I'm a sloppy java programmer > //ps.close(); > } > > To reproduce run the attached program > java derbyStress > Both client and server will grow until the connection is closed. > > It is likely that the fix for this will have to be in the client. The client > does not send protocol to close the prepared statement, but rather reuses the > PKGNAMCSN on the PRPSQLSTT request once the prepared statement has been > closed. This is how the server knows to close the old statement and create a > new one. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
