The configuration file in DB2 is not overwritten by the image file (1)

This article describes how to avoid the configuration files in the target database from being overwritten by the image files in the DB2 database. For your reference, I hope to help you.

When restoring the database BACKUP image file created by DB2 using the BACKUP command from the RESTORE command to a target database with different names, DB2 copies the configuration files in the source database to the restored target database, which overwrites the original configuration parameter settings of the database. This provides a method to prevent the configuration files in the target database from being overwritten by the image files.

1. Concepts of database seed values:

Before introducing this method, we should first introduce the concept of database seed. It is the unique identifier of the database. During the entire lifecycle of the database, this value will remain unchanged. The seed value is specified by the database manager during database creation. During restoration operations, DB2 always uses the seed value in the backup image. To obtain the seed value in the backup image, run the DB2ckbkp command to query it from the output.

When a full backup image of a DB2 database is restored to an existing database, the aliases, names, and seed values of the two databases may be different, the recovery utility performs a series of operations on the database. One of the operations is to compare the two seed values of the source and target databases. If the seed values are different, copy the database configuration file in the backup image to the target database to overwrite the original configuration parameters. If the two values are the same, keep the configuration file in the target database.

2. Explain the implementation steps in conjunction with the instance:

The following is an example to illustrate how to avoid restoration of the DB2 database backup image to different databases. The configuration file of the target database is overwritten by the image. Here, the source database name is SAMPLE and the target database name is TEST, the following is an example of how to modify the database parameter UTIL_HEAP_SZ:

· Obtain the seed value of the source database:

1. view the value of UTIL_HEAP_SZ in the source database:

DB2 get db cfg for sample | find/I "util _"
Utility heap size 4 kb) (UTIL_HEAP_SZ) = 5000

2. Full offline backup of the source database: