postgresql-table-design

PostgreSQL table design applies normalization, appropriate data types, and robust constraints to enforce data integrity. Start with a UUID primary key using gen_random_uuid(), add TIMESTAMPTZ columns for created_at and updated_at, select precise types like NUMERIC for decimals and BIGINT for large integers, and define NOT NULL, UNIQUE, and foreign key constraints to prevent invalid data.

UUID primary keys provide global uniqueness without coordination and work well for distributed systems, while BIGINT offers smaller storage and faster comparisons for centralized databases. Choose UUID for microservices and systems requiring collision-free IDs across nodes; use BIGINT when storage and query performance are critical and IDs are generated sequentially.

Normalization reduces redundancy by organizing data into separate tables with foreign keys, improving maintainability and consistency. Balance this against denormalization for read-heavy workloads by strategically caching frequently joined columns, but only after profiling; start normalized and denormalize only where analysis shows performance gains justify the trade-off.

PostgreSQL schema design recommends TIMESTAMPTZ for timestamps to handle timezones correctly, NUMERIC for precise financial values, TEXT for variable-length strings, BIGINT for large integers, and DOUBLE PRECISION for floating-point math. Avoid generic types; precise type selection improves storage efficiency, query performance, and prevents silent precision loss.

Index foreign key columns to accelerate joins and prevent sequential scans on lookups. Create indexes on FK columns that are frequently used in WHERE clauses or JOIN conditions; consider MVCC behavior when indexing to ensure visibility tuples don't bloat your indexes, and profile to confirm the index reduces query time before deploying.

Use NOT NULL to prevent missing critical data, UNIQUE for fields that must be distinct, CHECK constraints to validate business rules, and PRIMARY KEY and FOREIGN KEY constraints to enforce relationships. These constraints prevent invalid states at the database level, reducing application logic and ensuring consistency across all queries.