SQL database recovery models determine the kind of backup that can be initiated for the database. This is a database property that controls the log of transactions, backup of transactions and restoration operations on the transactions. The recovery model can be simple, full and bulk-logged.
By default, SQL Windows Server uses a simple recovery model. Logs are not maintained and SQL automatically claims log space. The changes since the most recent backup remains unprotected and in the event of disaster, the data may be lost. The Full recovery model requires the maintenance of logs and no work will be lost as the data can be recovered to an arbitrary point in time, provided backups have been maintained up to that point in time. Bulk-logged recovery model is complementary to full recovery model and permits high performance bulk-copy operations on the database. Logs use up minimal space as a result if the log is damaged, all operations up to the point of damage may have to be redone. Point in time recovery of data is not possible.
SQL Server backup plug-in uses full, differential and log modes to backup the SQL database to the Cloud. The Full backup, as the name implies, backs up all data to the Cloud server. This is known as “seeding”. All differential backups use the “full backup” as a point of reference for backing up changed information to the remote backup server. The log lists out changes that have been made to the database since the last successful backup of data. The restoration process uses both the original “seeded” data and the differential backup to restore the complete data set requested.
Cloud backup software uses the .NET SQL server manager API (Application Program Interface) and VSS (Volume Shadow Copy) to create a read-consistent Full backup of the SQL database. Users are presented with options for selecting the databases they want to sync, set up retention policies and synchronization schedules, enable multi-threaded data transfer and activate access logs, alerts and reports. Every incremental SQL backup request uses binary comparison to scan all the pages across the VSS and derive the changed set of data that must be updated to the Cloud backup server. Once the backup process is successful the logs can be truncated and the log space can be released.
The Cloud backup commitment lean principles in backup management make for simpler, faster and cheaper backup and recovery of SQL databases.