From: pgsql-general-ow...@postgresql.org [mailto:pgsql-general-ow...@postgresql.org] On Behalf Of Dane Foster Sent: Tuesday, January 26, 2016 2:39 PM To: pgsql-general <pgsql-general@postgresql.org> Subject: [GENERAL] Can PostgreSQL use multi-column index for FK constraint validation?
Hello, If I have a primary key index of the form: (col1, col2, col3) and a foreign key constraint of the form: FOREIGN KEY (col1, col2) REFERENCES foo ON DELETE CASCADE ON UPDATE CASCADE should I create a separate index (col1, col2) or is PostgreSQL capable of using the primary key's index? Thanks, Dane Columns in proposed index on FK (col1, col2) are in the same order (and in the beginning) of PK index. So, no need for additional index (col1, col2). Regards, Igor Neyman
