# Dynamic and static properties

A property in Derby can be dynamic or static.

Most properties are dynamic; that means you can set them while Derby is running, and their values change without requiring a reboot of Derby. In some cases, this change takes place immediately; in some cases, it takes place at the next connection.

Some properties are static, which means changes to their values will not take effect while Derby is running. You must restart or set them before (or while) starting Derby.

Note: Properties set in the derby.properties file and on the command line of the application that boots Derby are always static, because Derby reads this file and those parameters only at startup.

Only properties set in the following ways have the potential to be dynamic:

- As database-wide properties
- As system-wide properties via a Properties object in the application in which the Derby engine is embedded

Parent topic: Derby property reference
Related concepts
Scope of Derby properties
Derby properties