# TypeScript performance (Prisma ORM v7) (/docs/orm/v7/more/troubleshooting/typescript-performance)

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Optimize TypeScript compilation performance when working with large Prisma schemas

Location: ORM > v7 > More > Troubleshooting > TypeScript performance

When working with large database schemas, changing how you reference the `PrismaClient` type can cut compile time and memory use substantially:

| Approach             | Types                     | Instantiations            | Memory                    | Compile Time              |
| -------------------- | ------------------------- | ------------------------- | ------------------------- | ------------------------- |
| **Direct Reference** | 269,597                   | 2,772,929                 | 395MB                     | 1.86s                     |
| **typeof technique** | 222 (**99.9% reduction**) | 152 (**99.9% reduction**) | 147MB (**62% reduction**) | 0.41s (**78% reduction**) |

## Problem [#problem]

In enterprise applications with extensive database schemas, Prisma's generated types can become enormous. A schema with 50+ tables and deep relationships can lead to:

* Compilation times exceeding several minutes
* High memory usage during type checking
* IDE responsiveness degrading significantly
* CI/CD pipelines timing out on type checks

## Solution [#solution]

Use TypeScript's `typeof` operator instead of direct type references when defining function parameters that accept PrismaClient instances.

### Problematic approach for large schemas [#problematic-approach-for-large-schemas]

```typescript
import { PrismaClient } from "../prisma/generated/client";

const saveFn = async (prismaClient: PrismaClient) => {
  // Function implementation
};

const client = new PrismaClient();
await saveFn(client);
```

### Optimized approach with `typeof` [#optimized-approach-with-typeof]

```typescript
import { PrismaClient } from "../prisma/generated/client";

const saveFn = async (prismaClient: typeof client) => {
  // Function implementation
};

const client = new PrismaClient();
await saveFn(client);
```

## Why `typeof` is more efficient [#why-typeof-is-more-efficient]

The `typeof` operator creates a more efficient type resolution path:

1. **Type Query Reference**: `typeof client` performs a type query that obtains the widened type of the identifier expression, avoiding the need to re-expand the complex `PrismaClient` type definition
2. **Reduced Type Instantiation**: The compiler avoids expanding the entire Prisma type hierarchy for each type check (resulting in a 99.9% reduction in instantiations)
3. **Memory Efficiency**: Referencing an existing instance's inferred type requires significantly less memory than expanding complex conditional types and generics

## Conclusion [#conclusion]

When working with large Prisma schemas, prefer `typeof` type queries over direct references to `PrismaClient`. The 78% compilation time reduction shown here grows as the schema gets larger.

## Benchmark [#benchmark]

The complete benchmark code is available at:
[https://github.com/ToyB0x/ts-bench/pull/211](https://github.com/ToyB0x/ts-bench/pull/211)

## Related pages

- [`Bundler issues`](https://www.prisma.io/docs/orm/v7/more/troubleshooting/bundler-issues): Solve ENOENT package error with vercel/pkg and other bundlers
- [`Check constraints`](https://www.prisma.io/docs/orm/v7/more/troubleshooting/check-constraints): Learn how to configure CHECK constraints for data validation with Prisma ORM and PostgreSQL
- [`GraphQL autocompletion`](https://www.prisma.io/docs/orm/v7/more/troubleshooting/graphql-autocompletion): Get autocompletion for Prisma Client queries in GraphQL resolvers with plain JavaScript
- [`Many-to-many relations`](https://www.prisma.io/docs/orm/v7/more/troubleshooting/many-to-many-relations): Learn how to model, query, and convert many-to-many relations with Prisma ORM
- [`Next.js`](https://www.prisma.io/docs/orm/v7/more/troubleshooting/nextjs): Best practices and troubleshooting for using Prisma ORM with Next.js applications