tailieunhanh - SQL Anywhere Studio 9- P8

Tham khảo tài liệu 'sql anywhere studio 9- p8', công nghệ thông tin, cơ sở dữ liệu phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 386 Chapter 9 Protecting C mirror - renamed mirror log file from 3rd backup G bkup - backup database file from 1st backup G bkup - backup transaction log file from 1st backup G bkup - backup transaction log file from 2nd backup G bkup - backup transaction log file from 3rd backup Note The BACKUP DATABASE command renames and restarts the current mirror log file in the same way it does the current transaction log file but it does not make a backup copy of the mirror log file. That s okay The mirror log files are really just copies of the corresponding transaction logs anyway and three copies are probably sufficient. Live Log Backup A live log backup uses to continuously copy transaction log data to a file on a remote computer. The live log backup file will lag behind the current transaction log on the main computer but not by much especially if the two computers are connected by a high-speed LAN. If other backup files are written to the remote computer and a live log backup file is maintained it is possible to use that remote computer to start the database in case the entire main computer is lost only a small amount of data will be lost due to the time lag between the current transaction log and the live log backup. The following is an example of a Windows batch file that starts on the remote computer this batch file is executed on that computer and the startup folder is remote_test9 the same folder that is mapped to the G drive on the main computer as described earlier. A local environment variable CONNECTION is used to hold the connection string for dbbackup to use and the LINKS parameter allows to reach across the LAN to make a connection to the database running on the main computer. The -l parameter specifies that the live log backup is to be written to a file called in the folder remote_test9 bkup. The last parameter bkup meets the .