Running the following statements in sqlplus will create two sql files with statements for disabling and enabling FK constraints in current schema.
set echo on
set verify on
set feedback off
set heading off
set pagesize 0
set linesize 1000
spool disable_constraints_script.sql
select 'alter table '||table_name||' disable constraint '||constraint_name||';' from user_constraints where constraint_type in ('R');
spool enable_constraints_script.sql
select 'alter table '||table_name||' modify constraint '||constraint_name||' enable novalidate;' from user_constraints where constraint_type in ('R');
