They serve two different environments. The prisma db push is not to be used in your production environment, as stated in the docs

db push uses the same engine as Prisma Migrate to synchronize your Prisma schema with your database schema, and is best suited for schema prototyping. The db push command:

1. Introspects the database to infer and executes the changes required to make your database schema reflect the state of your Prisma schema.

2. By default, after changes have been applied to the database schema, generators are triggered (for example, Prisma Client). You do not need to manually invoke prisma generate.

3. If db push anticipates that the changes could result in data loss, it will:

• Throw an error
• Require the --accept-data-loss option if you still want to make the changes

Note: db push does not interact with or rely on migrations. The migrations table will not be updated, and no migration files will be generated.

The prisma migrate dev is used in you local environment, as explained in the docs

migrate dev is a development command and should never be used in a production environment.

This command:

1. Replays the existing migration history in the shadow database in order to detect schema drift (edited or deleted migration file, or a manual changes to the database schema)
2. Applies pending migrations to the shadow database (for example, new migrations created by colleagues)
3. Generates a new migration from any changes you made to the Prisma schema before running migrate dev
4. Applies all unapplied migrations to the development database and updates the _prisma_migrations table
5. Triggers the generation of artifacts (for example, the Prisma Client)

The migrate dev command will prompt you to reset the database in the following scenarios:

• Migration history conflicts caused by modified or missing migrations
• The database schema has drifted away from the end-state of the migration history

If you have any other question regarding this, there is this comparison in the docs explaining when to use one or the other.

Hi @dotsinspace 👋

Thank you for raising this question.

Prisma's db push is primarily used for quickly prototyping and iterating on schema design locally. It does not address the use case of transferring large volumes of data between databases. While Prisma can help manage your database schema and interact with your database through Prisma Client, the specific use case of transferring large volumes of data from one database to another typically falls outside the direct use case Prisma is designed for.

For transferring data between databases, especially with the scale you're describing (billions of entries), a custom script might still be the most flexible and controlled approach. This could involve exporting the data from the source database and importing it into the target database, potentially using intermediate formats like CSV or JSON, depending on the databases involved and their support for import/export formats.

If this answers your question, it would be great if you could mark this Discussion as answered to indicate that it has been resolved.

Otherwise please let us know how else we can help you further or close the Discussion if it was resolved in some other way 🙏

Hi @rainnfx 👋

Thank you for raising this question.

It's not a stupid question at all! Managing schema changes without data loss is a common concern. The prisma db push command is designed to quickly synchronize your Prisma schema with your database schema. However, it does not generate migration files and is best suited for prototyping in a development environment. When prisma db push detects changes that could result in data loss (e.g., adding a required field without a default value), it will prompt you to reset the database.

You should use prisma migrate commands instead of prisma db push. This command helps you create and apply migrations during development. This command helps you create and apply migrations during development.

• Expand and Contract Pattern:

This pattern allows you to evolve your schema without downtime and data loss. It involves making non-destructive changes first (e.g., adding a nullable field) and then gradually evolving the schema.
You can read more about this pattern in the documentation.

I would recommend you to pass the schema file location while invoking npx prisma db push command.

npx prisma db push --schema='/location/to/schema.prisma'

Also, I would recommend you to run the command from root location of your project.

Here's a reference for db push command.