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The Trino best practices page describes several ways to optimize Trino queries.

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Use EXPLAIN for query plans

It’s useful to inspect the query plan before running heavy queries. EXPLAIN shows how Trino handles joins, filters, and table scans. 
EXPLAIN SELECT * FROM employees1 WHERE salary > 5000;
For deeper insight, a JSON format reveals scan ranges, cost estimates, and pushdown behavior. 
EXPLAIN (FORMAT JSON)
SELECT department_id, AVG(salary)
FROM employees1
GROUP BY department_id;

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Push down predicates

Write filters so you can push it down into Iceberg or Hive metadata. This reduces I/O and avoids unnecessary S3 reads.
  • Bad example: 
    WHERE CAST(start_date AS DATE) = DATE '2025-01-15'
  • Good example: 
    WHERE start_date = DATE '2025-01-15'

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Prune columns

Select only the required columns. This helps minimize shuffles and reduces the amount of data pulled from S3.
  • Bad example: 
    SELECT * FROM employees1;
  • Good example: 
    SELECT employee_id, salary FROM employees1;

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Optimize joins

As previously described, use join hints when table sizes are predictable. Broadcast a small dimension table to speed up the join, and apply partitioning for large fact-to-dimension joins.
  • Bad example: 
    SELECT /*+ PARTITIONED(f, dim) */ ...
  • Good example: 
    SELECT /*+ BROADCAST(dim) */ ...

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Limit large scans

Apply filters and LIMIT clauses during early data exploration to avoid scanning entire Iceberg tables.
  • Bad example: 
    SELECT * FROM employees1;
  • Good example: 
    SELECT *
FROM employees1
WHERE salary > 3000
LIMIT 100;

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Pre-compute aggregations with CTAS or materialized views

For dashboards or recurring workloads, pre-compute heavy aggregations using Create Table as Select (CTAS) or materialized views. This reduces the load on Trino and improves Superset’s responsiveness. 
CREATE TABLE analytics.employee_salary_by_department AS
SELECT department_id,
       COUNT(*) AS employee_count,
       SUM(salary) AS total_salary
FROM employees1
GROUP BY department_id;

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Additional resources

  • To get an overview of Trino, refer to the Trino in NexusOne page.
  • To learn practical ways to use Trino in the NexusOne environment, refer to the Trino hands-on examples page.
  • For more details about Trino, refer to the Trino official documentation.
  • If you are using the NexusOne portal and want to learn how to launch Trino, refer to the Launch a hosted app page.