Thank you for your answer César.
In fact, we're using IDS 9.40, so I haven't ONLINE option (...yet )
About creating the index before, my problem is not creating index and loading data in the same table. The situation is the following:
I have "A" and "B" tables. I'm creating an index in "A" table; meanwhile I'm loading data with dbload into "B" table. And then, "B" table loading process fails as it finds a lock in ¿¿¿sysdefaults table??? First of all, I don't understand why "CREATE INDEX" sentence place some exclusive locks on sysdefaults table. Actually, trying to do more tests, I've got the same situation with two "CREATE INDEX" sentences: one finishes successfully, but the other fails with the sysdefaults lock error.
I've tried to repeat the situation creating indexes and monitoring locks, but I've not been able to know in what cases "CREATE INDEX" command is locking sysdefaults table (sometimes it does, sometimes id doesn't...)
I would be very grateful if someone could help me with this matter.
Thank you in advance.
Luis.