Oracle : Ошибка ORA-01743

"only pure functions can be indexed"
*Cause: The indexed function uses SYSDATE or the user environment.
*Action: 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.

Попробовать перевести

Поискать эту ошибку на форуме