Dry run

Definition

A dry run is a rehearsal for a command, script, or process. It lets you check what would happen before you allow the command to write files, change data, send messages, or affect users.

Why it matters

Dry runs are useful when a task has risk. They help you catch mistakes early, especially before database changes, bulk updates, imports, or production operations.

Example in VCA

In VCA, a learner might run a script in dry-run mode to preview which records would be created before allowing the script to write to the database.

Another Real World Example

A developer might dry-run a migration or cleanup task to see how many records would be affected before running it for real.

Common mistakes

Assuming a command has a dry-run mode when it does not.
Skipping the real verification step after a dry run looks correct.
Running the real command against production by accident.
Trusting a dry run that does not check all side effects.
Forgetting that emails, webhooks, and external APIs may still need separate safety checks.