GBase 8a Query Optimization in Practice: EXPLAIN, Materialized Views, CTE, and Common Tuning Techniques

This article starts from real slow queries and explains how to read execution plans with EXPLAIN, use materialized views correctly, when to apply CTEs, and several high‑frequency query tuning tips in a gbase database.

1. Reading Execution Plans with EXPLAIN

Basic Usage

SELECT dept_id, SUM(amount)

FROM orders