I am planning to create a temporary table upload the data into the table. and then update the data using tables. Is this right approach please suggest
Looks like the right approach.
You can define an external table for reading the data in the file (You will have to move the file to DB server).
if data is not that huge, you can directly UPDATE or MERGE using the external table.
If data is huge, you could think of loading the exernal table data into a staging table using
INSERT INTO...SELECT .... FROM and then do MERGE/UPDATE
SQL Error: ORA-30926: unable to get a stable set of rows in the source tables
30926. 00000 - "unable to get a stable set of rows in the source tables"
*Cause: A stable set of rows could not be got because of large dml
activity or a non-deterministic where clause.
*Action: Remove any non-deterministic where clauses and reissue the dml.