# Improving Leapwork Studio Performance with the [UseBulkCopyForMssql] Flag in Leapwork Controller Configuration

## Overview
This article introduces a new optional configuration flag - UseBulkCopyForMssql that can be added to the Leapwork Controller configuration file to improve performance in scenarios where large and complex flows are managed within Leapwork Studio.

This enhancement is designed specifically for **Enterprise Edition** customers. The flag is **not applicable** to **Platform Edition** or **Trial Edition** users.

## Purpose
Enterprise users often experience slower responsiveness when opening or saving large flows (typically with more than 200 building blocks) or when viewing version histories with hundreds of versions. The UseBulkCopyForMssql flag leverages SQL Server’s bulk copy optimization to significantly improve database interaction performance in these cases.

## Configuration Details
- **Flag Name:** UseBulkCopyForMssql  
- **Location:** Controller configuration file (controller.config)  
- **Applicable Editions:** Enterprise Edition only  
- **Default Value:** False  
- **Supported Databases:** Microsoft SQL Server (MSSQL)

## Impact and Benefits
When UseBulkCopyForMssql is enabled (true), Leapwork Studio operations involving large data transfers to and from the Controller database execute significantly faster.

### Observed performance improvements include:
- **Opening large flows** (200+ building blocks): loads within a few seconds instead of extended wait times.
- **Saving large flows:** completes in seconds with no UI freeze or unresponsiveness.
- **Accessing Version History window** for large or frequently updated flows (200+ versions): opens smoothly without lag.
- **Version number updates** after saving large flows: processed almost instantly.

These improvements result in a more fluid and responsive user experience for power users managing complex automation assets.

## Support Guidance
If customers report slow performance when handling large flows:
1. Confirm they are using an **Enterprise Edition** license.
2. Verify the backend is **Microsoft SQL Server**.
3. Instruct them to enable UseBulkCopyForMssql in the Controller configuration file.
4. Restart the Leapwork Controller service.
5. Re-test Studio performance on large flows and version history access.

For any clarification, please contact our [Priority Support](mailto:prioritysupport@leapwork.com).