ORA-01743: only pure functions can be indexed
What triggered the Error:
The indexed function uses SYSDATE or the user environment.What should we do to fix it:
PL/SQL functions must be pure (RNDS, RNPS, WNDS, WNPS). SQL expressions must not use SYSDATE, USER, USERENV(), or anything else dependent on the session state. NLS-dependent functions are OK.