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Apr 2, 2023 · Big Data

Unlock Faster ODPS SQL: Proven UNION, COUNT DISTINCT, and Join Optimizations

This article walks through common ODPS SQL scenarios—union, count distinct, large‑table joins, mapjoin, and predicate placement—explains why naïve implementations can be inefficient, shows how to read and interpret execution plans, and provides concrete rewritten queries that dramatically improve performance and resource usage.