[ http://issues.apache.org/jira/browse/DERBY-1879?page=all ]
Daniel John Debrunner closed DERBY-1879. ---------------------------------------- > Save meta data related information for an EmbedResultSet at the plan level > instead of the ResultSet level improves performance. > ------------------------------------------------------------------------------------------------------------------------------- > > Key: DERBY-1879 > URL: http://issues.apache.org/jira/browse/DERBY-1879 > Project: Derby > Issue Type: Improvement > Components: JDBC, Performance > Reporter: Daniel John Debrunner > Assigned To: Daniel John Debrunner > Priority: Minor > Fix For: 10.3.0.0 > > Attachments: derby1879_diff.txt > > > EmbedResultSet creates and holds references to information that logically is > at the plan level, the same for all ResultSet's that use the same prepared > plan. Holding this information at the EmbedResultSet hurts performance and > memory usage as ResultSet objects are short lived. > Saving the ResultSetMetaData object in the ResultDescription object means a > single creation for the lifetime of the plan (shared across connections), > rather than once per ResultSet object as needed. > Saving the column name to position mapping added in DERBY-1862 in the > ResultDescription has a similar benefit, the map is set up once per prepared > plan, not once per executeQuery(). > With test changes (will attach patch soon), the performance of the derby1862 > test in DERBY-1876 improves by around 15% -- 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
