What you do when you can't get to insert data in tables with identity column
db2 alter table <table_name> alter column <column_name> restart with <max(column_value)>
1 - First step:
Check the max value of the column identity.
db2 select max(<column_identity_name>) from <table_name>)"
2 - First step:
Set a value major than max(<column_identity_name>) to <column_identity_name>
db2 alter table <table_name> alter column <column_name> restart with <value>