Title: Providing two implementations of the same service for sequential effects

// Depends on SqlClient
const CreateDatabase = Effect.gen(function* () {
    const sql = yield* PgClient.PgClient
    // ... check if "main" exists and exit early, otherwise
    yield* sql.unsafe("CREATE DATABASE main")
}).pipe(
    Effect.provide(
        PgClient.layer({
            ...,
            database: "postgres",
        }),
    ),
)

// Depends on SqlClient
const RunMigrations = Effect.gen(function* () {...})

CreateDatabase.pipe(
    Effect.andThen(RunMigrations),
    Effect.provide([
        ...,
        PgClient.layer({
            ...,
            database: "main",
        }),
    ]),
    Effect.runPromise,
)