SQL Compare enables you to compare a backup with other data sources. This is useful, for example, when you want to retrieve the schema from a backup and compare it with your database without running a restore operation or copying the backup from a remote network.

If you are comparing two backups, you do not need SQL Server to be installed on your computer.

Note that:

• Comparing backups is available only in SQL Compare Professional edition.
• SQL Compare can retrieve the schema from full or differential backups. However, it does not support partial, filegroup, or transaction log backups.
• When you run a comparison using a backup, SQL Compare locks the backup files when it reads them, and you cannot overwrite, move, or delete them.
• SQL Compare does not read the log records of backup files, so if the database schema was modified while the backup was being created, it may not be shown as modified in the comparison results.
• You can specify a backup as the target; however, note that backups cannot be modified.

Comparing and synchronizing backups

You can:

• compare a backup with another data source
  For more information, see: Setting data sources.

• create a synchronization script from a backup

When you have selected a backup as the target, the synchronization wizard creates a script to update the database from which the backup was created. Backups cannot be modified directly.

When a backup is the source, and a database is the target, the synchronization script will synchronize the database with the backup.

For more information, see: Using the synchronization wizard.

Compatibility with backups

You can compare backups from SQL Server 2008, SQL Server 2005 and SQL Server 2000 databases. SQL Compare supports:

• native SQL Server backups

  You can use backups created with SQL Server native compression (including row-level, page-level and file-level compression). Note that SQL Server 2008 encrypted backups are not supported.

• SQL Backup backups

  You can use backups created with SQL Backup version 3 or later; you can use compressed or encrypted backups.

Note that when you set up a comparison that uses a backup, SQL Compare does not support tables that do not have a primary key, unique index, or unique constraint.