When does a temporary table often outperform a large CTE?

Problem Statement

Explanation

Many optimizers inline CTEs, so heavy subqueries can be recomputed. Persisting the step to a temp table lets you index it, reuse it, and control row counts. This can lower total work and give the optimizer better cardinality for later joins.

Code Solution

SolutionRead Only

CREATE TEMP TABLE recent AS
SELECT * FROM events WHERE ts>=NOW()-INTERVAL '7 days';
CREATE INDEX ON recent(user_id);
SELECT ... FROM recent r JOIN users u ON u.id=r.user_id;

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Query Plans & Performance Tuning

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When does a temporary table often outperform a large CTE?

Problem Statement

Explanation

Code Solution

Practice Sets

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When does a temporary table often outperform a large CTE?

Problem Statement

Explanation

Code Solution

Practice Sets

Related Questions

Which SQL statement retrieves all columns and rows from a table named employees?

Which clause filters rows before aggregation and affects which rows are grouped?

What is the default sort order when ORDER BY is used without ASC or DESC?

Which construct is commonly used to paginate results in SQL engines like Postgres and MySQL?

Which predicate correctly checks for missing values in standard SQL?

More from SQL & Databases

Master Interviews
Anywhere, Anytime