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6. Considerations when querying
Given Superset's shared usage, it's crucial to optimize queries and datasets while creating dashboards to ensure a seamless experience for all users
Specify What You Need: Be clear about the data you need and only request the necessary fields to minimize the amount of data returned.
Avoid SELECT *: Avoid using
SELECT *as it retrieves all columns, which can be inefficient. Instead, explicitly list the columns you need.Filter Early: Apply filters and conditions early in your query to reduce the dataset size before any complex operations are performed.
Use Joins Wisely: Be mindful of how you use joins, as they can be resource-intensive. Use INNER JOIN, LEFT JOIN, etc., as appropriate for your data relationships.
Aggregate Smartly: When performing aggregations, consider the efficiency of GROUP BY and aggregation functions like COUNT, SUM, AVG, etc.
Limit Results: Use the LIMIT clause to restrict the number of rows returned, especially when working with large datasets.
Monitor Performance: Regularly monitor query performance, identify bottlenecks, and optimize slow queries.
Avoid Nested Subqueries: Be cautious when using nested subqueries, as they can be complex and impact performance.
Consider Data Types: Be aware of data types and conversions when filtering or manipulating data.
Caching: Implement caching for frequently used queries to reduce database load.