In most production environments the default search of the system catalog tables can return a very large amount of data, so that each time a CLI/ODBC application opens a database there can be a considerable delay. Even on a typical test database, the delay can easily be of the order of 25 seconds or so.
Measure this delay initially without having any of the above CLI keywords set, while remembering to discount connect time and especially the long delays that can occur when a DB2 client issues its first ever connection to a new database - autobinding can often take several minutes.
How you proceed next depends on the structure of your data and your organization. In some cases you can use DBNAME, SCHEMALIST, and TABLETYPE in combination to limit the search for use by a particular application or group of applications. For example, if production DBA clients usually access tables under a given DBNAME and schema then this is easy to specify.
CLISCHEMA provides the best performance advantages for most users. For this reason we would generally recommend using CLISCHEMA in a production environment, since it is much easier to set up and modify CLISCHEMA's user tables through the CLI command Line Interface (db2cli.exe) and its bldschem support command. See also db2ocat Catalog Optimizer Tool.