Postgres 19's New REPACK Command Can Make pg_dump Silently Skip a Table

Sun, 27 Sep 2026 09:00:00 +0530

PostgreSQL 19 Beta 4 shipped on September 24 with REPACK, a new SQL command that reclaims table bloat and reorganizes storage in place, folding VACUUM FULL and CLUSTER into one command.[1] The version anyone actually wants is REPACK (CONCURRENTLY) tablename: it rewrites a bloated table without taking the table offline, something Postgres core has never done and that the community has covered for years with the pg_repack extension. Nine days after the beta shipped, a bug report on the pgsql-hackers mailing list showed the sharpest edge of that feature: run pg_dump while a REPACK CONCURRENTLY is mid-flight, and pg_dump can exit successfully having written a backup file where the target table has a COPY header and zero data rows.[2] The table has 1,000 rows. The dump has none. Nothing in the exit code says so.

Mvcc on Kuldeep Pisda

Postgres 19's New REPACK Command Can Make pg_dump Silently Skip a Table