PostgreSQL 19 adds built-in REPACK for online table reorganization

PostgreSQL 19 introduces the REPACK command, including REPACK CONCURRENTLY, enabling table reorganization with minimal downtime. It also supports index-based reorganization similar to CLUSTER, with an approach comparable to Oracle's DBMS_REDEFINITION.

• REPACK CONCURRENTLY builds a compact copy and syncs changes on the fly
• Requires a primary key or suitable NOT NULL unique index
• DDL on the target table is blocked during REPACK
• Extra disk space is needed for a new copy of table and indexes