# TypeScript performance (Prisma ORM v6) (/docs/orm/v6/more/troubleshooting/typescript-performance)

Optimize TypeScript compilation performance when working with large Prisma schemas

Location: ORM > v6 > 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

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

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

### 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`

```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

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

When working with large Prisma schemas, prefer type queries (`typeof`) over direct type references. The 78% compilation time reduction demonstrated here scales exponentially with schema complexity.

## Benchmark

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

## Related pages

- [`Bundler issues`](/guides/more-4-v6-more-troubleshooting-bundler-issues): Solve ENOENT package error with vercel/pkg and other bundlers
- [`Check constraints`](/guides/more-4-v6-more-troubleshooting-check-constraints): Learn how to configure CHECK constraints for data validation with Prisma ORM and PostgreSQL.
- [`GraphQL autocompletion`](/guides/more-4-v6-more-troubleshooting-graphql-autocompletion): Get autocompletion for Prisma Client queries in GraphQL resolvers with plain JavaScript
- [`Many-to-many relations`](/guides/more-4-v6-more-troubleshooting-many-to-many-relations): Learn how to model, query, and convert many-to-many relations with Prisma ORM
- [`Next.js`](/guides/more-4-v6-more-troubleshooting-nextjs): Best practices and troubleshooting for using Prisma ORM with Next.js applications.

## Related pages

- [Authentication & Tools](./authentication-tools-index.md)
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- [Changelog](../changelog.md)
- [Concepts](./concepts-index.md)
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- [Contract Authoring](./contract-authoring-index.md)
- [Core Concepts](./core-concepts-index.md)
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- [DB commands](./db-commands-index.md)

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