Running dbcc checks and performing database backups protects the integrity and recoverability of your Adaptive Server databases.
Use dbcc checkstorage to run regular consistency checks on large databases when the amount of time you require to perform consistency checks is less than the amount of time required for dbcc checkalloc or dbcc checkdb to complete. dbcc checkstorage performs a fast consistency check, but it is not as thorough as dbcc checkalloc or dbcc checkdb See “Preparing to use dbcc checkstorage” in Chapter 10, “Checking Database Consistency,” in the System Administration Guide, Volume 2, and the Reference Manual: Commands.
You can also run the following sample C shell script which calls several isql scripts to help you do this:
#!/bin/csh -f if ( -e dbcc_mail.out) then rm dbcc_mail.out endif foreach i (*.dbcc) isql -Usa -Ppassword < $i > dbcc_out if ( ‘grep -c ‘Msg 25[0-9][0-9]’ dbcc_out’ ) then echo "There are errors in" $i >> dbcc_mail.out cat dbcc_out >> dbcc_mail.out else echo "Backing up " $i:r >> dbcc_mail.out isql -Usa -Ppassword < $i:r.backup endif end mail -s "Backup Report" jjones < dbcc_mail.out
The first set of scripts (one for each database with a file name appended with .dbcc) runs dbcc checkalloc and dbcc checkdb for each database and sends the messages to an output file called dbcc_out.
For example, the script master.dbcc runs dbcc to check the master database:
dbcc checkalloc (master) go dbcc checkdb (master) go
The C shell script then runs the grep command to find 2500-level error messages in the dbcc output. The results of the grep command go into an output file called dbcc_mail.out.
Next, the script invokes an isql backup script for each database for which no 2500-level errors occurred and adds the “Backing up database_name” line to dbcc_mail.out. For example, the script master.backup backs up the master database:
use master go dump database master to master_dump go
You may want to add appropriate dump transaction commands to your scripts.
If there are 2500-level error messages, the script does not back up the database. At the end of the script, dbcc_mail.out is mailed to the System Administrator “jjones,” who then has a record of fatal dbcc errors and successful backups.
You can tailor the sample shell and isql scripts to suit the needs of your installation.
To have the scripts execute automatically, edit the crontab file, and add an entry similar to this:
00 02 * * * /usr/u/sybase/dbcc_ck 2>&1
This example executes a C shell script called dbcc_ck every morning at 2:00 a.m.