HiRDB hasn't equivalents for SYS_CONTEXT function. SQLWays leaves it as is and adds message /* SQLWays: Could not convert 'SYS_CONTEXT' */.

Oracle:

select SYS_CONTEXT('USERENV', 'SESSION_USER') from t;

HiRDB:

select SYS_CONTEXT('USERENV', 'SESSION_USER') from t;
/* SQLWays: Could not convert 'SYS_CONTEXT' */