Data page checksums
Checksums can be added to data pages to assist corruption detection caused by storage system errors. They can only be set at initdb time and for the entire database cluster; it is not possible to later convert the cluster or an individual database to use checksums.
To determine whether checksums are enabled, query the preset GUC
Alternatively, from PostgreSQL 9.6 execute e.g. "
SELECT data_page_checksum_version FROM pg_control_init()"; for all versions this value is reported as "Data page checksum version" by pg_controldata. "0" means not enabled.