Tune the new version for performance and adjust queries

After backing up the new server, you can tune the database server to maximize performance. If your queries are slower after the upgrade, there are steps you can take to adjust your configuration and queries.

If your queries are slower after an upgrade, find out what changed that affects your configuration and adjust your configuration and queries as necessary:

• Compare the default values in the new onconfig.std file to values in your previous installation, and make any necessary adjustments (see New configuration parameters).
• If you created sample queries for comparison, use them to analyze the performance differences between the old and new database servers and to determine if you need to adjust any configuration parameters or the layout of databases, tables, and chunks.
• If you changed your applications, check to see if the changes led to slower performance.
• If you changed your hardware, operating system, or network settings, determine if you need to adjust any related settings or environment variables.
• Make sure that you ran necessary update statistics after upgrading:
  • Drop data distributions if necessary when upgrading
  • Optionally update statistics on your tables after migrating