(as the previous answer) and here’s the code:
ALTER TABLE atable
ADD (tmpdetails CLOB);
UPDATE atable SET tmpdetails=details;
COMMIT;
ALTER TABLE atable DROP COLUMN details;
ALTER TABLE atable
RENAME COLUMN tmpdetails TO details;
(as the previous answer) and here’s the code:
ALTER TABLE atable
ADD (tmpdetails CLOB);
UPDATE atable SET tmpdetails=details;
COMMIT;
ALTER TABLE atable DROP COLUMN details;
ALTER TABLE atable
RENAME COLUMN tmpdetails TO details;