Restoring Your Databases

Once you have created a database and made a full backup, you can restore the database when necessary. Sybase IQ restores the database to its state as of the automatic CHECKPOINT at the start of the backup.

• Before You Restore
  Conditions must be met before you can restore a database.
• The RESTORE Statement
  To restore a database, use the RESTORE statement.
• Restoring in the Correct Order
  When you restore from a full backup, every block in use at the time the backup was made is written to disk. When you restore from an incremental backup, only the blocks that changed between the previous backup (or the previous full backup) and this backup are written to disk.
• Reconnecting After You Restore
  Sybase IQ requires the DBF parameter and database file name in order to connect to a database under certain circumstances.
• Renaming the Transaction Log after you Restore
  When you rename or move all other files in the database, you should also do the same for the log file.
• Validating the Database After You Restore
  To ensure that tapes have been restored in the correct order, you should run the stored procedure sp_iqcheckdb after you finish restoring your database.
• Restore Requires Exclusive Write Access
  Once RESTORE starts, no other users are allowed to access the specified database.
• Displaying Header Information
  You can display the contents of the header file by using the RESTORE statement with the CATALOG ONLY option and no FILE clauses.
• Recovery from Errors During Restore
  If an incremental restore fails early in the operation, the database is still usable (assuming it existed and was consistent before the restore).
• Verifying a Database Backup
  Sybase IQ includes a mechanism that verifies an existing Sybase IQ version 12.6 or later database backup using the VERIFY clause of the RESTORE SQL statement.
• Backups and Symbolic Links (UNIX Only)
  In backups involving symbolic links, Sybase IQ may create dbspaces in a directory other than the one desired.