Import table data in right order to avoid violating foreign key constraints

Question

Gentlemen
I am trying to import table data into an existing 10g schema using datapump import in table mode.
However, in order to avoid violating foreign key constraints, the tables must be loaded in a specified order. I tried specifying the order in the TABLES parameter:
TABLES=table1,table2,table3 etc.
However, datapump seems to chose its own order leading to errors like the following:
ORA-31693: Table data object "SCHEMAX"."TABLE3" failed to load/unload and is being skipped due to error:
ORA-02291: integrity constraint (SCHEMAX.TABLE3_TABLE1#FK) violated - parent key not found
I want to try to avoid having to disable all foreign keys because there are hundreds of them.
Any advice?
Yours
Claus Jacobsen, Denmark

Answer 1

Thanks Anantha.
Since I am only loadding data (the constraints are already defined in the target database), I am not sure whether this approach would work. Meanwhile I have solved the problem of moving data from one system to another using another, tedious and far from elegant approach that I would prefer to not eloborate on:-)
However, I have also discovered another probable reason why the foreign key constraints were violated, other than wrong order of table data loading. It turns out almost every single table in the schema contains a trigger supposed to generate a unique row ID from a sequence on insert such as:
CREATE OR REPLACE TRIGGER "SCHEMAX"."TABLEX#B_I_R"
BEFORE INSERT
ON TABLEX
FOR EACH ROW
DECLARE
BEGIN
SELECT tablex_seq.nextval INTO :NEW.ID FROM dual;
END;
If the import mechanism fires this trigger, and the sequences in the source and the target systems are not synchronized, then I guess that referred records a more than likely to end up with wrong ID's compared to the row ID's in the referring rows?
Spooky. Anybody can confirm this theory?
Yours
Claus
Message was edited by:
user586249