DB2 Compression in Information Analyzer

Answer

It is a newly added feature in Information Server 87 release for db2 database. When some large tables are profiled in Information analyzer, the reference tables created in analysis database takes much space. Retrieving data from these reference tables will also takes much time.

Using DB2 compression which is introduced in from DB2 9 helps to reduce space occupied by these tables upto 40%. Another advantage is there is a considerable performance increase for data retrieval from these compressed tables.

Usage in IA:
We should enable a property manually to use this feature in Information Analyzer located in the below location.

<WebSphere installed Location> \WebSphere\AppServer\profiles\InfoSphere\installedApps\<Machine Name>Node01Cell\IAServices.ear.ear\conf

with file name.
'ia.server.properties'

The following property should be changed manually from false to true.

# db2 compression
server.enableDB2Compression=false

After modifying the property WebSphere application Server must be restarted to read the property.

Goto this location

<WebSphere installed Location> \WebSphere\AppServer\bin

and run
(For windows user)
stopServer.bat server1 -user <was user> -password <was password>
startServer.bat server1 -user <was user> -password <was password>

(For non windows user)
stopServer.sh server1 -user <was user> -password <was password>
startServer.sh server1 -user <was user> -password <was password>

After following the above steps we can perform regular operations in Information analyzer like column analysis etc.