PostgreSQL 19 lets admins enable data checksums without server downtime

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PostgreSQL 19, currently in beta and expected for general release around September–October 2026, introduces two new SQL functions — pg_enable_data_checksums() and pg_disable_data_checksums() — that allow administrators to toggle data checksums on a live database without shutting it down. Previously, enabling or disabling checksums required stopping the server and running the standalone pg_checksums tool, which caused an outage of over a second even on databases under 1GB. The new functions spawn a background worker that processes pages while normal queries continue running, though the full conversion still takes a few seconds of wall time on small datasets. Additionally, PostgreSQL 19 changes the default behavior of initdb so that all newly created clusters have data checksums enabled automatically, removing the need to opt in at creation time. The update trades a brief guaranteed outage for a slightly longer conversion window during which the database remains fully available.

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