Idempotent
Voici la liste des commandes qui sont idempotentes, utiles pour écrire des migrations.
| CREATE OR REPLACE | CREATE IF NOT EXISTS | DROP IF EXISTS | |
|---|---|---|---|
| AGGREGATE | Y (12) | N | Y |
| CAST | N | N | Y |
| COLLATION | N | Y | Y |
| CONVERSION | N | N | Y |
| DATABASE | N | N | Y |
| DOMAIN | N | N | Y |
| EVENT TRIGGER | N | N | Y |
| EXTENSION | N | Y | Y |
| FOREIGN DATA WRAPPER | N | N | Y |
| FOREIGN TABLE | N | Y | Y |
| FUNCTION | Y (7.2) | N | Y |
| GROUP | N | N | Y |
| INDEX | N | Y (9.5) | Y |
| LANGUAGE | Y | N | Y |
| MATERIALIZED VIEW | N | Y (9.5) | Y |
| OPERATOR | N | N | Y |
| OPERATOR CLASS | N | N | Y |
| OPERATOR FAMILY | N | N | Y |
| PROCEDURE | Y (11) | N | Y (11) |
| ROLE | N | N | Y |
| RULE | Y | N | Y |
| SCHEMA | N | Y | Y |
| SEQUENCE | N | Y (9.5) | Y |
| SERVER | N | Y (10) | Y |
| STATISTICS | N | Y (10) | Y |
| TABLE | N | Y | Y |
| TABLE AS | N | Y | N/A |
| TABLESPACE | N | N | Y |
| TEXT SEARCH CONFIGURATION | N | N | Y |
| TEXT SEARCH DICTIONARY | N | N | Y |
| TEXT SEARCH PARSER | N | N | Y |
| TEXT SEARCH TEMPLATE | N | N | Y |
| TRANSFORM | Y (9.6) | N | Y (9.6) |
| TRIGGER | Y (14) | N | Y |
| TYPE | N | N | Y |
| USER | N | N | Y |
| USER MAPPING | N | Y (10) | Y |
| VIEW | Y | N | Y |