You have an RI on the table.
You got to learn to utilize IBM to get answers to this easy question.
Download at Least Message Ref pdf files
IBM - DB2 9 for Linux, UNIX and Windows manuals
Or simply go here DB2 Database for Linux, UNIX, and Windows
and put your error code there
or do on the command line
db2 "? SQL0668N"
1 Execute the SET INTEGRITY statement with the IMMEDIATE CHECKED
option on table "<table-name>" to bring the table out of the
Set Integrity Pending No Access state. For a user
maintained materialized query table, execute the statement
with the IMMEDIATE UNCHECKED option instead of the
IMMEDIATE CHECKED option.
IBM Certified DBA on DB2 for Linux, UNIX, and Windows
DB2 v220.127.116.11 os 18.104.22.168