To connect to IBM DB2 Universal Database for Linux, UNIX, and Windows, or IBM Cloudscape, or Apache Derby, you must install an IBM DB2 Universal Database client on the same computer on which you are running PHP. The extension has been developed and tested with DB2 Version 8.2.
To connect to IBM DB2 Universal Database for z/OS or iSeries, you also require IBM DB2 Connect or the equivalent DRDA gateway software.
The user invoking the PHP executable or SAPI must specify the DB2 instance before accessing these functions. You can set the name of the DB2 instance in php.ini using the ibm_db2.instance_name configuration option, or you can source the DB2 instance profile before invoking the PHP executable.
If you created a DB2 instance named db2inst1 in /home/db2inst1/, for example, you can add the following line to php.ini:
bash$ source /home/db2inst1/sqllib/db2profile