A practitioner's guide to PostgreSQL table partitioning based on 4 years of production experience. Covers why to partition (table size thresholds, vacuum performance, data lifecycle management), why range-based partitioning is preferred over hash or list partitioning, and the pitfalls of default partitions including locking issues. Explains how to attach/detach partitions efficiently using NOT VALID check constraints to avoid long-running locks. Deep-dives into partition-wise joins: aligning partition boundaries across related tables, enabling enable_partitionwise_join, and denormalizing associative tables to include the 'leading figure' key for efficient joins. Also covers index management on partitioned tables, foreign key behavior surprises, automated partition management, and archiving strategies using detach-and-drop or foreign data wrappers.