Backup Copy Protection

System Security Principles

Protection by Partial Backup

How to Make a Complete Database Backup

One of the ways to protect the database against data loss is to backup the database file on a regular basis. Different database file backup methods and their properties are described below. The method of data backup from tables by exporting data is not described here.

Manually Copy the Database File

You can backup the database by copying the database file manually to a different location. You can do this only when the 602SQL Server is not currently running on this database, otherwise database integrity cannot be guaranteed.

One-time Backup from the Client Environment

In Control Panel, the System / Tools / Automatic backups page, it is possible to press the Backup now button. If the backup parameters are specified in the same window (see the following paragraph - at least the backup directory parameter), the backup is made irrespective of the backup schedule.

Automatic Database Backup

You can setup the Backup... runtime parameters from the control panel folder System / Tools / Automatic backups (or by calling the Get_property_value API function). These backups can be made periodically after or at a specific time and day.

In the example, database backups are made every 12 hours or on workdays (Mon-Fri 2 times a day at 6:00 AM and 6:00 PM) and on Sunday and Saturday at 12:30 PM. Day specification classifier:

1	Daily
2	Monday
3-8	Tuesday to Sunday
9	Workdays (Mon-Fri)
10	Weekends (Sat, Sun)

A backup is created in the folder specified by the BackupDirectory parameter. When the backup count crosses the limit specified by the BackupFilesLimit parameter, the oldest backup will be deleted. The backup files are named in the form YYMMDDhh.mmX, where YYMMDD is year, month, day, and hhmm is the hour and minute. X is A to D and specifies different parts of the database file.

You can restore the database files from the backup files using the Restore now! button in the Management tab on the Database management dialog accessible from the pop-up menu (the 602SQL Server must be stopped before this action can be performed).

If during server operation the backup creation starts in blocking mode, execution of most operations is suspended during the time necessary for creation of file copy. In case of non-blocking mode, you can continue with work.

Immediately after the backup is saved, the system trigger _on_backup is called. It allows you to react either to a successful or unsuccessful backup (e.g. by sending an e-mail to the administrator). Backup compression (see the following) will not affect the results of _on_backup.

Backup Compression

If backup compression is turned on by the BackupZip parameter, each new backup file is compressed immediately after the backup and if specified, the compressed backup is moved to the folder specified by the BackupZipMoveTo parameter.

File compression and moving the backup runs asynchronously in a separate thread, so it does not block other processes on the 602SQL Server.

The compressed backup files are named in the form of YYMMDDhh.mmz.

The backup count is valid even for compressed backups, however the folders BackupZipMoveTo and BackupDirectory must be different.

Backup Directly from an Application

A database backup can be explicitly called by a database application (e.g. if a user selects this option from a menu or when the number of database changes crosses a specified limit).

An explicit backup is made by the Backup_database_file function. Most of the server operations are suspended, just like when running an automatic backup.

Intervention to Backup

Using the _ON_SYSTEM_EVENT generic trigger with event_num parameter equal to 1, you can influence (and even revoke) backup creation.

Blocking x Non-blocking Backup

The database server backup can be created in two possible modes:

• blocking backup - it is not permitted in this mode to read from and to write to the database, i.e. the clients are prevented from work till backup completion. Backup is created at the top speed.
• non-blocking backup (hot backup) - within this mode, it is possible to read from and to write to the database, however, the execution is slower. However, the modifications are not written to currently backed-up database, but to an auxiliary file; after backup completion, they are automatically recorded back to the database (i.e. modifications executed during backup are not included into the backup). Since version 10.0.2, the non-blocking backup mode is set by default.

The backup modes are selected in Control Panel, System / Tools / Automatic backups page using Do not block the server operation... switch or using Get_property_value) function, you can set server properties to NonblockingBackups.

Backup Copy Protection

System Security Principles

Protection by Partial Backup