Improve performance by storing data that takes time and resources to retrieve and is accessed frequently. Using extra memory can sometimes be a better option that repeated retrievals. Use caution and care when creating a cache for storing this data. Keep in mind that a poorly designed cache can negatively impact performance.
For example, most IPM clients need to display and open the IPM subtree of folders many times during a typical session. You can improve performance by storing the entry identifiers for each of these folders.