HypoPG - Hypothetical Indexes

Giriş

Açıklaması şöyle

We all know how indexes can optimize query plans if used carefully. Since index creation requires resources, it would have been nice to have a way to know beforehand whether postgres will use those indexes or not.

HypoPg, a postgres extension lets you do just that. It can be used to create a hypothetical index without costing you resources and enables you to analyse the index performance.

Kurulum

Şöyle yaparız

CREATE EXTENSION hypopg;

hypopg_create_index metodu

Şöyle yaparız. Sequence Scan veya Index Scan kullanıldığını gösterir

SELECT * FROM hypopg_create_index('CREATE INDEX ON mytable (id)');
EXPLAIN SELECT * FROM mytable WHERE id = 1;    

Diğer

Açıklaması şöyle

hypopg_reset() — to clear the previous effects of other indexes

hypopg_drop_index(indexrelid) — to remove your backend’s hypothetical indexes

hypopg_hide_index(oid) — to hide an index

hypopg_unhide_index(oid) — to restore the index