A schema snapshot is a compact file that contains all the schema information for a database. The schema information is stored in a proprietary format and can only be read by IDERA SQL Schema Compare. The schema snapshot does not contain data, only schema information.
Schema snapshots allow you to maintain a history of schema changes. You can take schema snapshots at different points in time and then you can compare those snapshots to each other or compare the snapshots to the live database to get a clear an accurate picture of the "evolution" of the database schema.
To take a schema snapshot, simply move the mouse over the name of the database on the left panel of the Workspace and you will see a "camera" icon appear on the side of the database name. Click on that icon to take the snapshot - you will be asked to choose the name of the snapshot and the location where you wish to save it.
Before comparing snapshots to each other or to live databases you will need to add the snapshots you need to the workspace. The Add Snapshots functionality can be accessed from the ribbon (the Home tab).
On the Add Snapshots dialog window that appears, click Browse... to browse to the location where the snapshot(s) you wish to add to the workspace have been stored. You can select as many snapshots as you want from different locations. For each snapshot you select the application will display the file name, the database the snapshot was taken from, the date when the snapshot was taken, and SQL Server version.