Optimizing Query Performance
When you submit a query to Vertica for processing, the Vertica query optimizer automatically chooses a set of operations to compute the requested result. These operations together are called a query plan. The choice of operations can drastically affect the run-time performance and resource consumption needed to compute the query results. Depending on the properties of the projections defined in your database, the query optimizer can choose faster and more efficient operations to compute the query results.
As your database grows over time, queries could degrade in performance. It is important to monitor the performance of your queries—especially queries that are run frequently or access large data sets.
If you experience query performance issues, you should:
- Analyze the statistics and the histogram for your database tables and run Database Designer. Supply the queries that are experiencing performance problems.
- Review the QUERY_EVENTS system table. This table identifies whether there are issues with the planning phase of a query.