Time costs of a query

You can adjust a few, but not all, of the response-time effects of actions that the database server performs when processing a query.

The following costs can be reduced by optimal query construction and appropriate indexes:
  • Sort time
  • Data mismatches
  • In-place ALTER TABLE
  • Index lookups

For information about how to optimize specific queries, see Improving individual query performance.


Copyright© 2018 HCL Technologies Limited