DB2 tuning overview

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You must identify the DB2® configuration parameters that you must tune to improve DB2 database performance.

DB2 serves as the data storage component of IBM® Verify Directory. You can improve the performance of directory server by tuning DB2 database that is associated with the instance.

You can use the following suggestions for tuning DB2:

  • DB2 buffer pools: DB2 buffer pools are DB2 data caches. Each buffer pool is a data cache between the applications and the physical database files. In IBM Verify Directory, version 6.2 and later, buffer pools are automatically tuned by default.For information about buffer pool, see DB2 buffer pool.
  • Optimization and organization: After a directory server is loaded with data or after updates, it is important to update database statistics and organization for DB2 to run optimally. For more information, see Optimization and organization of database.
  • Indexes: Indexes help locate data on disk in lesser time, providing a significant boost to performance. For information about how to create indexes, see DB2 indexes.
Attention: You must store the DB2 log on a physical disk drive separate from the data. For improved data-integrity and performance, store the DB2 log and the data on separate drives. Use the following command to set the path to the DB2 log file directory. 
DB2 UPDATE DATABASE CONFIGURATION FOR database_alias USING NEWLOGPATH path

Be sure that the database instance owner has write access to the specified path or the command might fail. For more information about using the DB2 commands, see Tuning DB2 and LDAP caches.

After the DB2 database is restored, you must retune the server unless the optimizations on a backed up DB2 database are known. When you run DB2 backup, the optimizations on the database are preserved in the backed up database. For example, DB2 system statistics and DB2 parameter settings are preserved in the backed up database. When you back up a directory server by using the idsdbback command, the server configuration is backed up along with the DB2 database. Users can also use the idsperftune command to improve the performance of the directory server. For more information about the idsperftune command, see The performance tuning tool.