[ http://issues.apache.org/jira/browse/DERBY-818?page=comments#action_12363286 ]
Daniel John Debrunner commented on DERBY-818: --------------------------------------------- There is a similar issue for the code to ensure a stream is only fetched once. The boolean array streamUsedFlags is allocated on every ResultSet and reset on every move position call. In many cases there will be no streaming columns and getXXXStream will never be called. Fixing this allowed a 2-3% improvement in the same VALUES clause. The fix is to allocate the array only on demand when a getXXXStream call is made. WIll address this as part of this issue.Will also add comments for this stream re-use code. > Read-only embedded ResultSets incur performance penalty due to updateable > ResultSet code. > ----------------------------------------------------------------------------------------- > > Key: DERBY-818 > URL: http://issues.apache.org/jira/browse/DERBY-818 > Project: Derby > Type: Improvement > Components: JDBC, Performance > Reporter: Daniel John Debrunner > Assignee: Daniel John Debrunner > Priority: Minor > Attachments: derby818patch.txt > > The fields columnGotUpdated and copyOfDatabaseRow are allocated and > maintained in EmbedResultSet for every ResultSet but they are only required > if the result set is updateable. I saw a 5% improvement in execution rate on > a simple VALUES clause when fixing this. -- 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
