Database Technology

Christophe Pettus introduces three new Global Configuration parameters designed to log only a random sample of queries rather than every statement. These settings—log_min_duration_sample, log_statement_sample_rate, and log_transaction_sample_rate—allow DBAs to capture representative query statistics without the overhead of recording every single execution. This approach helps identify performance patterns in high-throughput environments where full logging would be prohibitively expensive.

• Use log_statement_sample_rate to log only a fraction of statements, reducing I/O and storage overhead.
• Apply log_min_duration_sample to filter sampled queries by execution time, focusing on slow operations.
• Enable log_transaction_sample_rate to sample entire transactions, preserving context for multi-statement workloads.
• Aggregate statistics from samples can reveal performance trends without the cost of full query logging.

PostgreSQL 19 adds four new system views to enhance monitoring and observability, marking the most significant update to catalog views since versions 13 and 14. The new additions include pg_stat_lock, pg_stat_recovery, pg_stat_autovacuum_scores, and pg_dsm_registry_allocations. These views provide granular insights into locking behavior, recovery processes, autovacuum efficiency, and dynamic shared memory allocations. Although the release is still in beta with potential schema changes, these tools represent a major step forward for database administrators tracking internal performance metrics.

• Four new system views target specific bottlenecks: locks, recovery, autovacuum, and dynamic shared memory.
• pg_stat_autovacuum_scores offers a new metric for evaluating vacuum efficiency beyond traditional stats.
• pg_dsm_registry_allocations exposes dynamic shared memory usage, critical for extension developers.
• Schema columns may still change before GA; verify against final release notes before production implementation.
• These views align with increased observability focus in PG19, reducing reliance on external monitoring agents.

Christophe Pettus introduces two new GUCs to control how bound parameters are logged alongside SQL statements and errors. These settings allow administrators to limit the length of parameter values recorded in logs, addressing privacy and performance concerns when debugging. This provides finer granularity for managing sensitive data exposure in audit trails.

• New GUCs let you cap logged bind parameter lengths for statements and errors.
• Reduces risk of exposing sensitive PII in database logs by truncating values.
• Improves log readability by preventing excessively long parameter dumps.
• Appears in PostgreSQL 19 development cycle as of September 2026.