DB2 is a database manager that runs on Linux, Unix, and Windows operating systems. It allows users to catalog databases, start and stop instances, and configure parameters. Key commands for managing DB2 include db2icrt for creating instances, db2idrop for dropping instances, db2ilist for listing instances, and db2set for setting configuration parameters at the global, instance, and node level. The db2set command provides centralized control over environmental variables.
6. Operating system:
- Red Hat Enterprise Linux (RHEL) 5 Update 2.0.4
- SUSE Linux Enterprise Server (SLES) 10 Service Pack 2
- SUSE Linux Enterprise Server (SLES) 11
- Ubuntu 8.0.4.1
Installation Pre-requisites (Linux!)
Disk space requirements: 500 to 1GB
Memory requirements: Minimum of 512 MB of RAM
Root (vs) Non-root installation
Users/Groups
11. Removes a DB2 instance that was created by db2icrt.
db2idrop - Drop Instance
Syntax:
You can only drop instances that are listed by db2ilist command
Example: db2idrop db2inst1
12. Lists all the instances that are created using the db2icrt command
db2ilist - List Instances
Syntax:
$ db2ilist -h
$ db2ilist
db2inst1
db2inst2
Gets data from /var/db2/global.reg
db2greg -dump
13. Login as the DB2 instance owner
db2start - Start Instance
. $DB2_HOME/db2profile
db2start
14. Login as the DB2 instance owner
db2stop - Stop Instance
Make sure you have all applications disconnected (db2 list applications)
$ db2stop
$ db2stop force (= db2 force application all + db2stop)
$ db2_kill
15. $ db2 get instance
$ db2 ? get dbm cfg
GET DATABASE MANAGER CONFIGURATION [SHOW DETAIL]
$ db2 get dbm cfg
$ db2 get dbm cfg | grep NUMDB
$ db2 update dbm cfg using NUMDB 10
$ db2 attach to db2inst1
$ db2 get dbm cfg show detail
$ db2 reset dbm cfg
DBM CONFIGURATION
18. Priority of DB2 Env/registry variables:
- OS environment set with set/export
- Node instance
- Instance
- Global
To read global profile: db2greg -dump
Detecting DB2 products installed: /usr/local/bin/db2ls *This internally checks global.reg file
SYSIBMADM.REG_VARIABLES admin view:
select substr(REG_VAR_NAME,1,35) NAME, substr(REG_VAR_VALUE,1,35) VALUE,
LEVEL from SYSIBMADM.REG_VARIABLES
REG_LIST_VARIABLES Table function:
SELECT CHAR(REG_VAR_NAME,35) AS REGVAR, CHAR(REG_VAR_VALUE,35) AS
VALUE,LEVEL FROM TABLE(REG_LIST_VARIABLES()) AS REG ORDER BY 3,1
Instance IDs should not be root or have password expired.
DB2DIR: DB2 installed location. You can find this using db2ls command
http://www-01.ibm.com/support/knowledgecenter/SSEPGG_10.5.0/com.ibm.db2.luw.qb.server.doc/doc/c0050566.html
The instance directory stores all information that pertains to a database instance. You cannot change the location of the instance directory once it is created. The directory contains:
The database manager configuration file (db2systm)
The system database directory
The node directory
The node configuration file (db2nodes.cfg)
Any other files that contain debugging information, such as the exception or register dump or the call stack for the DB2 database processes.
The installation process creates a default DB2 instance, which is defined by the DB2INSTANCE environment variable. However, instances can be created/dropped after installation.
Auto starting Instances: db2iauto -on instance_name
On LUW, an instance created by using db2icrt is set as a manual start.
ps -ef | grep ^db2inst1 | egrep -v "bash|sshd|grep“
reset dbm cfg: Resets the DBM configuration file to its default values
Location of DBM CFG file: ./sqllib/db2systm
Link: https://www.columbia.edu/sec/acis/db2/db2d0/db2d0160.htm
Instance node level profile registry: For partitioned databases
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To display help information for the command, use:
db2set ?
To list the complete set of all supported registry variables, use:
db2set -lr
To list all currently defined registry variables for this session, use:
db2set
To show the current session value of a registry variable, use:
db2set registry_variable_name
To delete the current session value of a registry variable, use:
db2set registry_variable_name=
To change a registry variable for this session only, use:
db2set registry_variable_name=new_value
To change a registry variable default for all databases in the instance, use:
db2set registry_variable_name=new_value -I instance_name
To change a registry variable default for all instances in the system, use:
db2set registry_variable_name=new_value -g
Note:The two parameters "-I" and "-G" cannot be used at the same time in the same command.
To change a registry variable default for a particular node in an instance, use:
db2set registry_variable_name=new_value -i instance_name node_number
To reset all registry variables for an instance back to the defaults found in the Global Profile Registry, use:
db2set -r registry_variable_name
To reset all registry variables for a node in an instance back to the defaults found in the Global Profile Registry, use:
db2set -r registry_variable_name node_number
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Instance node level profile registry: For partitioned databases
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To display help information for the command, use:
db2set ?
To list the complete set of all supported registry variables, use:
db2set -lr
To list all currently defined registry variables for this session, use:
db2set
To show the current session value of a registry variable, use:
db2set registry_variable_name
To delete the current session value of a registry variable, use:
db2set registry_variable_name=
To change a registry variable for this session only, use:
db2set registry_variable_name=new_value
To change a registry variable default for all databases in the instance, use:
db2set registry_variable_name=new_value -I instance_name
To change a registry variable default for all instances in the system, use:
db2set registry_variable_name=new_value -g
Note:The two parameters "-I" and "-G" cannot be used at the same time in the same command.
To change a registry variable default for a particular node in an instance, use:
db2set registry_variable_name=new_value -i instance_name node_number
To reset all registry variables for an instance back to the defaults found in the Global Profile Registry, use:
db2set -r registry_variable_name
To reset all registry variables for a node in an instance back to the defaults found in the Global Profile Registry, use:
db2set -r registry_variable_name node_number
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%ia: If instance attachment exists, the authid of the current instance attachment; otherwise a null string
%i: Local alias of instance
%da: If database connection exists, the authid. Else, null string
%d: Database aliase
%n: New line character
