pg_checksums is a small tool based on the pg_verify_checksums program
available in PostgreSQL from version 11 on. In addition to verifying checksums,
it can activate and deactivate them. The former requires all database blocks
to be read and all page headers to be updated, so can take a long time on a
large database.
The database cluster needs to be shutdown cleanly in the case of checksum activation or deactivation, while checksum verification can be performed online.
PostgreSQL versions since 9.3 are supported, the November 8th 2018 PostgreSQL point release is required.