Sessions & Tracks : DigiBase : Indexing DigiBase Databases : Indexing while Browsing

Indexing while Browsing
The first time you open a Volume browser for a volume or folder that has never been indexed, Pro Tools automatically begins to fill the database for that level of the volume. Files and folders appear in the browser Items List, along with metadata in the columns for each item. Indexing continues until you either close the browser, or until that folder is completely indexed.
The next time you open that browser, metadata for items that have already been indexed is visible immediately. If the browser or folder was closed before indexing was complete, or if the contents of the folder have changed since the last time it was browsed, Pro Tools automatically updates the database the next time it is opened. This way, the database is always up to date for the folder you are browsing. (View the Task Manager to see current activity.)
Indexing while Browsing saves time because it only fills the database for items on the level of the volume that you are currently browsing. For example, if you are browsing the root level of the volume, it indexes only the folders and files on the root level. If you open a folder, Pro Tools indexes just the items in that folder. As a result, a database is only indexed for the parts of the volume that you have browsed. However, searches are faster and more complete when a volume is already completely indexed.