Optimize queries
Optimize SQL and InfluxQL queries to improve performance and reduce their memory and compute (CPU) requirements. Learn how to use observability tools to analyze query execution and view metrics.
Why is my query slow?
Query performance depends on time range and complexity. If a query is slower than you expect, it might be due to the following reasons:
- It queries data from a large time range.
- It includes intensive operations, such as querying many string values or
ORDER BY
sorting or re-sorting large amounts of data.
Strategies for improving query performance
The following design strategies generally improve query performance and resource use:
-
Follow schema design best practices to make querying easier and more performant.
-
Query only the data you need–for example, include a
WHERE
clause that filters data by a time range. InfluxDB v3 stores data in a Parquet file for each measurement and day, and retrieves files from the Object store to answer a query. The smaller the time range in your query, the fewer files InfluxDB needs to retrieve from the Object store. -
Downsample data to reduce the amount of data you need to query.
Some bottlenecks may be out of your control and are the result of a suboptimal execution plan, such as:
- Applying the same sort (
ORDER BY
) to already sorted data. - Retrieving many Parquet files from the Object store–the same query performs better if it retrieves fewer - though, larger - files.
- Querying many overlapped Parquet files.
- Performing a large number of table scans.
Analyze query plans to view metrics and recognize bottlenecks
To view runtime metrics for a query, such as the number of files scanned, use the EXPLAIN ANALYZE
keywords and learn how to analyze a query plan.
Analyze and troubleshoot queries
Learn how to analyze a query plan to troubleshoot queries and find performance bottlenecks.
Was this page helpful?
Thank you for your feedback!
Support and feedback
Thank you for being part of our community! We welcome and encourage your feedback and bug reports for InfluxDB and this documentation. To find support, use the following resources:
Customers with an annual or support contract can contact InfluxData Support.