Know the properties of the database

select * from sys.V_$VERSION;

know the properties of the database using DBLink

select * from sys.V_$VERSION@DBLink;

TO_DATE in SQL

Alternatively, you may use TO_DATE explicitly:

insert into x
values(99, to_date('1998/05/31:12:00:00AM', 'yyyy/mm/dd:hh:mi:ssam'));

The general usage of TO_DATE is:

TO_DATE('', '')

Grant access to use a SQL function from different schema

grant execute on SchemaName.FunctionName to SchemaName (where we need to access)