- Derby does not currently allow the named or unnamed window
specification to be specified in the OVER()
clause, but requires an empty parenthesis. This means the
function is evaluated over the entire result set.
- The ROW_NUMBER function cannot currently be used in a WHERE
- Derby does not currently support ORDER BY in subqueries, so
there is currently no way to guarantee the order of rows in the
SELECT subquery. An optimizer override can be used to force the
optimizer to use an index ordered on the desired column(s) if
ordering is a firm requirement.
I see these possibly relevant fixes:
Also are there still performance considerations with ROW_NUMBER?
Are there still other concerns with ROW_NUMBER?