This post explains how the PostgreSQL optimizer works and highlights some important techniques it uses to speed up queries, such as constant folding, function inlining, join optimization, join order determination, join pruning, and optimized sorting for ORDER BY.
Table of contents
PostgreSQL constant foldingPostgreSQL query optimizer: function inliningFunction stability: VOLATILE vs. STABLE vs. IMMUTABLEEquality constraintsView inlining and subselect flatteningOptimizing joins in PostgreSQLDetermine the join strategyMaking use of sorted outputPartition pruning and constraint exclusion at workConclusion…Sort: