SkipMigrations

Disables the automatic database migration that normally runs inside UsePostgres. When called before UsePostgres(), the schema migration step is skipped entirely.

Signature

public static TraxEffectBuilder SkipMigrations(
    this TraxEffectBuilder builder
)

Returns

TraxEffectBuilder -- the same builder instance for chaining. Call UsePostgres() after this method.

Example

services.AddTrax(trax => trax
    .AddEffects(effects => effects
        .SkipMigrations()
        .UsePostgres(connectionString)
    )
    .AddMediator(typeof(MyTrain).Assembly)
);

When to Use

Use SkipMigrations() in environments where database migrations are managed externally:

• AWS Lambda runners -- cold start time is critical; migrations add 500ms--3s+ of blocking I/O on every cold start, even when no migrations are pending
• Serverless functions (Google Cloud Run, Azure Functions) -- same cold start concern
• Read-only replicas -- the function connects to a read replica that should never be migrated
• CI/CD-managed migrations -- migrations run as a separate deployment step before application startup

Running Migrations Separately

DatabaseMigrator.Migrate() is a public static method that can be called from any context:

using Trax.Effect.Data.Postgres.Utils;
 
// In a CI/CD script, setup Lambda, or API startup:
await DatabaseMigrator.Migrate(connectionString);

In the default setup (without SkipMigrations()), this is called automatically inside UsePostgres(). When you call SkipMigrations(), you are responsible for ensuring migrations run elsewhere before the application handles requests.

Remarks

• Must be called before UsePostgres() in the fluent chain. UsePostgres() checks the MigrationsDisabled flag at call time.
• All other registrations (NpgsqlDataSource, IDbContextFactory, IDataContext, effects) are unaffected -- only the migration step is skipped.
• The flag survives builder promotion to TraxEffectBuilderWithData, so it works correctly with method chaining.

Package

dotnet add package Trax.Effect.Data.Postgres