# Use patch files to customize Universal Tracker configuration

You must use patch files to add or change configuration settings. Sitecore merges the patch files with the Sitecore configuration file to create the configuration that is used at runtime.

The configuration files in Sitecore make up the default configuration. When you add a patch file to adjust or add settings, you can copy the folder structure from the individual plugin (the folder path under sitecore) into the main applications and add your own configuration files to extend the configuration provided by any plugin.

For example, when you configure the SQL Server connection string, instead of editing the \sitecore\Sitecore.Tracking.SqlServer\Config\config.xml, you must use a patch file:

1. Create a folder in the root of the application and name it config.

2. Add a file to the folder and name it, for example, deployment.xml .

3. Inside the deployment.xml file, add XML nodes which match those from the SQL plugin and fill in the ConnectionString node value:

<Settings>
<Sitecore.Tracking.SqlServer>
<SqlServerTrackingInteractionCache>
</Settings>