You can look up any error message from the command line with "db2 ? sqlxxxx" (where xxxx is the SQLCODE with no sign and leading 0 to make it 4 digits long)
You can also use db2 “? SQLxxxx” | more
The Linux command – more – allows paging of text one screen at a time
An example
DB2 SQL Error: SQLCODE=-805, SQLSTATE=51002, SQLERRMC=NULLID.SYSLH203 0X5359534C564C3031, DRIVER=3.53.70 db2 ? SQL805 Returned SQL0805N Package "" was not found.
With an in-depth explanation and User Response
DB2 error tips