Verifying stored information.
WHAT TO TEST
Data written matches what was submitted Constraints are enforced Transactions commit and roll back correctly Migrations apply successfully Queries return correct results
WHY CONSTRAINTS SPECIFICALLY
Applications frequently rely on them, and a missing constraint permits invalid data silently.
WHAT TO VERIFY ABOUT TRANSACTIONS
That a failure partway leaves no partial change.
HOW TO TEST THAT
Force a failure mid-operation, and inspect the data.
WHAT TO TEST ABOUT MIGRATIONS
Applying to a database containing realistic existing data Reversal, where supported Duration, at production volume
WHY DURATION MATTERS
A migration locking a large table can cause an outage.
WHAT TO TEST ABOUT CONCURRENCY
Simultaneous operations on the same record.
WHAT THAT CATCHES
Lost updates and race conditions.
HOW TO TEST IT
Run identical operations concurrently, repeatedly.
WHAT TO VERIFY ABOUT DATA OVER TIME
That values remain consistent That derived data matches its source That deletions remove everything intended
WHAT TO AUTOMATE
Consistency checks, run regularly.
WHAT TO ALERT ON
Any inconsistency, which should be impossible.
