This has been an issue with Toad for a little while, and whilst it’s not a massive bug, I know it’s caused at least one person an issue. This picture demonstrates the issue:
Both queries are valid forms of LAG in 11.2 and above, and both run correctly; it’s just that Toad reports one as having a syntax issue. Oracle list both forms as acceptable: http://docs.oracle.com/cd/E11882_01/server.112/e41084/functions082.htm#i1327527
Is there any chance of correcting this so that both of the above forms of the LAG and LEAD analytic functions show as syntactically correct?