The Ultimate Guide to High Availability with MariaDB

Optimizations for derived tables

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Contents

  1. Derived merge optimization ==
    1. The idea ===
  2. See also

Derived tables are subqueries in the FROM clause. Prior to MariaDB 5.3/MySQL 5.6, they were too slow to be usable. In MariaDB 5.3/MySQL 5.6, there are two optimizations

  • Derived table merge
  • Automatic derived table indexing

which provide adequate performance.

Derived merge optimization

The idea

See also

Optimizing Subqueries in the FROM Clause in MySQL 5.6 manual

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