Database migration in production in Django - Step-by-Step Execution

Concept Flow - Database migration in production

Write migration files

↓

Test migrations locally

↓

Backup production database

↓

Put app in maintenance mode

↓

Run migration commands

↓

Verify migration success

↓

Bring app back online

This flow shows the safe steps to update a production database schema using Django migrations.

Execution Sample

Django

python manage.py makemigrations
python manage.py migrate --noinput
# Backup DB
# Maintenance mode on
# Run migrate
# Maintenance mode off

This code sequence creates migration files, applies them without prompts, and manages production safety steps.

Execution Table

Step	Action	Command/Operation	Result	Notes
1	Create migration files	python manage.py makemigrations	New migration files created	Detects model changes
2	Test migrations locally	python manage.py migrate	Database updated locally	Ensures no errors
3	Backup production DB	pg_dump or equivalent	Backup file created	Safety step before changes
4	Enable maintenance mode	Custom command or config	App stops serving requests	Prevents user changes during migration
5	Run migrations in production	python manage.py migrate --noinput	Database schema updated	No prompts to avoid hangs
6	Verify migration success	Check logs and DB schema	No errors found	Confirms migration applied
7	Disable maintenance mode	Custom command or config	App resumes normal operation	Users can access app again
8	Exit	All steps completed	Production DB updated safely	Process finished

💡 All migration steps completed successfully, production database schema updated without downtime.

Variable Tracker

Variable	Start	After Step 1	After Step 3	After Step 5	Final
Migration files	None	Created	Created	Created	Created
Local DB schema	Old	Updated	Updated	Updated	Updated
Production DB backup	None	None	Created	Created	Created
Production DB schema	Old	Old	Old	Updated	Updated
App status	Online	Online	Online	Maintenance mode	Online

Key Moments - 3 Insights

Why do we backup the production database before running migrations?

Backing up ensures you can restore data if migration causes errors or data loss, as shown in step 3 of the execution_table.

Why use --noinput when running migrations in production?

The --noinput flag prevents the migration command from waiting for user input, avoiding hangs during automated deployment (step 5).

What is the purpose of maintenance mode during migration?

Maintenance mode stops users from making changes during migration, preventing conflicts or partial updates (step 4 and 7).

Visual Quiz - 3 Questions

Look at the execution_table, what is the app status after step 5?

A Online

B Maintenance mode

C Offline

D Unknown

💡 Hint

Check the 'App status' variable in variable_tracker after step 5.

At which step is the production database backup created?

A Step 3

B Step 1

C Step 5

D Step 7

💡 Hint

Look at the 'Production DB backup' variable in variable_tracker and the execution_table step descriptions.

If we skip enabling maintenance mode, which step would be missing from the execution_table?

A Step 6

B Step 2

C Step 4

D Step 8

💡 Hint

Maintenance mode is enabled at step 4 according to the execution_table.

Concept Snapshot

Django production migration steps:
1. Create migration files with makemigrations.
2. Test migrations locally.
3. Backup production DB.
4. Enable maintenance mode.
5. Run migrate with --noinput.
6. Verify success and disable maintenance mode.
Always backup and prevent user changes during migration.

Full Transcript

This visual execution shows how to safely update a Django production database schema. First, migration files are created and tested locally. Then, a backup of the production database is made to protect data. The app is put into maintenance mode to stop user activity. Next, migrations run with no input to avoid hangs. After verifying success, maintenance mode is turned off and the app resumes normal operation. Variables like migration files, database schema, and app status change step-by-step to ensure a smooth update.