Creating New Snapshot

You can create any number of database snapshot using DBChangeManager by clicking the  New Snapshot at the top of every page, just below the main tab. A dialog as shown below will be seen:

Providing Snapshot Details

To create a snapshot for a live SQL Server database the following details are to be provided:

• Snapshot Name: Provide a unique and relevant name for the snapshot to be created, so that you could easily spot it back any time you need
• Server: Provide the Machine name (Host name) in which the SQL Server live database is running whose snapshot has to be taken. If the SQL Server instance is running a Port other than 1433, specify the same along with the Machine name and a colon. e.g. <machine_name>:<port_number>
• Connection Settings: You could login to the live SQL Server database either with Windows Authentication or SQL Server Authentication. Choose the appropriate radio button based on the authentication type that you want to use.
  • SQL Server Authentication (default): If you choose SQL Server authentication then provide the appropriate SQL Server user name and password to login. You cannot use this option if you do not have a separate SQL Server login account present in the database. (Refer SQL Server manual to know about creating a separate SQL Server login)
  • Windows Authentication: If you choose Windows authentication, DBChangeManager would use the credentials of the machine in which the DBChangeManager Server is running and would pass it to the SQL Server for authentication. The machine in which DBChangeManager Server is running should have a windows authentication account in the SQL Server database that is to be connected for successful login.
  • Test Connection: Once you choose the appropriate authentication type and have provided the required details, click on 'Test Connection' to test whether DBChangeManager server can connect to the SQL Server database with the provided connection details. If there is an error in connection you will be appropriately notified about it. You need a valid database connection to further proceed with creating a snapshot.
• Database: Choose/Type the SQL Server database to be taken as snapshot, in the 'Database' field. You could fetch the existing databases present in the machine by clicking on the 'Refresh' link.

Creating the Snapshot:

Once you provide the database connection details, you could create the snapshot by clicking on the 'Create' button at the bottom of the New Snapshot dialog. DBChangeManager would perform the following steps to create the snapshot:

• Fetch the schema objects from the SQL Server database
• Script the schema objects in a proprietary snapshot XML file format
• Save the Snapshot XML in the DBChangeManager server machine with the given name

Snapshots will be created specific to the DBChangeManager users login which created it. A snapshot created by one user will not be available to another user.

As mentioned earlier, Snapshots can be used as a source for schema comparison using DBChangeManager. Snapshots can be compared with another Snapshot or with a live database or with an SQL Script file. Snapshot based schema comparisons are faster and can be done without the need for database connectivity (offline). Note that you cannot synchronize a snapshot.

You can also save the snapshot file for versioning. DBChangeManager will generate an SQL script file equivalent to that of the Snapshot that will be saved.

You can access and manage all the snapshots that are created using DBChangeManager using the Manage Snapshots option discussed in the next chapter