PostgreSQL

Working rules

• Preserve raw bytes as bytes when fidelity matters; choose parsed types separately for querying.
• Treat deployed migrations as immutable and account for old and new application versions during rollout.
• Check lock duration and transaction scope; protect read-modify-write paths against concurrent updates.
• Match index predicates and NULL semantics to every writer and migration query.
• Measure query changes with representative data and actual plans; verify invariants as database outcomes.

Data Type Defaults