Postgres 19 Shifts Default TOAST Compression from pglz to LZ4
PostgreSQL 19 plans to replace the legacy pglz algorithm with LZ4 as the default compression method for TOAST and heap storage. The database employs a unified compression framework that automatically compresses variable-length types like JSONB and TEXT by default. Index compression remains opportunistic, triggering only when individual keys exceed specific size thresholds rather than compressing every entry.
LZ4 replaces pglz as the default TOAST compression in Postgres 19 for better performance.