PostgreSQL 18 on Amazon Aurora and Amazon RDS: Security, monitoring, and developer enhancements

This article explores security, monitoring, and developer enhancements in PostgreSQL 18 for Amazon Aurora and RDS, complementing performance improvements from Part 1.

• MD5 password authentication deprecated in favor of SCRAM-SHA-256; new md5_password_warnings parameter helps identify affected roles
• Enhanced parallel worker monitoring via new pg_stat_database and pg_stat_statements columns to track worker launch success rates
• pg_stat_subscription_stats now tracks seven specific logical replication conflict types for easier diagnostics
• pg_upgrade automatically preserves optimizer statistics, eliminating post-upgrade performance degradation
• uuidv7() generates timestamp-ordered UUIDs that eliminate B-tree index bloat from random insertions
• Parallel streaming now default for logical replication subscriptions, reducing lag for large transactions
• idle_replication_slot_timeout automatically invalidates abandoned replication slots to prevent WAL accumulation
• COPY command adds REJECT_LIMIT for controlled error tolerance and LOG_VERBOSITY silent option
• OLD and NEW aliases in RETURNING clauses capture before-and-after values in single DML statements

PostgreSQL 18 strengthens operational efficiency and developer productivity across security, observability, and replication features for Aurora PostgreSQL and RDS for PostgreSQL.