I have seen the documetation about ISDATE funtion but i can't call this function in oracle.
My DB version
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
PL/SQL Release 11.2.0.4.0 - Production
"CORE 11.2.0.4.0 Production"
TNS for Linux: Version 11.2.0.4.0 - Production
NLSRTL Version 11.2.0.4.0 - Production
select isdate('20161005') from dual;
ORA-00904: "ISDATE": invalid identifier
00904. 00000 - "%s: invalid identifier"
*Cause:
*Action:
Error at Line: 59 Column: 8