Restore in a general IT context is the process of copying backup files from secondary storage such as a tape, zip disk or other backup media onto a hard disk. You have to perform a restore in order to return data to its original condition if files have been deleted or damaged. A restore operation can also recreate data at a new location. In a database context, restore means to recreate a database using backup files.
You can restore a database is a number of ways. Depending on the circumstances, a DBA may choose to perform a piecemeal or a complete restore. A complete restore involves a full restore of the entire database. Furthermore, the entire database is offline for the duration of a full restore. All data is recovered to a consistent where all parts of the database are synchronized and there are no uncommitted transactions.
According to Microsoft Developer Network, when using the full recovery model, you must restore all transaction log backups as well as recover the database after you restore your data backup. A database can be restored to a specific recovery point within one of these log backups. The recovery point can be a particular date and time, a specified transaction or a log sequence number.
A piecemeal restore makes it possible for databases with multiple filegroups to be restored and recovered in stages. Piecemeal restore involves a series of restore sequences and involves a series of checks to ensure that the database will be consistent.
Application management industry leader Idera offers several data restore technologies, including Bare-Metal Restore and SQL Safe Instant Restore. SQL Safe InstantRestore lets you to bring a database online almost instantly while the restore continues in the background. With InstantRestore, the system immediately starts the transactional part of a database restore, making the application available to users by accessing data from the backup copy as required, but defers actual data file (MDF) restoration until the database is back online.