after migrating our database from oracle 9i to oracle11g, the developpers are worry that the behavior of the queries and pl/sql procedures/functions will change
in 9i, select salary,count(*) from emp group by salary, it will display the rows sorted by salary
in 11gi, select salary,count(*) from emp group by salary, it will display the rows not sorted by default, we have to add the clause order by salary.
somebody could give the list of other difference in behavior (SQL and PL/SQL) agter migrating from 9i to 11g
Tell your developers: garbage in - garbage out. In relational databases only ORDER BY ensures row order. If your developers relied on GROUP BY implemented by SORT and therefore returning ordered rows they had to realize code they wrote is Oracle release dependent and sooner or later code would require changes. And that "sooner or later" is now reality. In newer versions ORACLE can do GROUP BY via SORT or via HASH. And if it is done via HASH - don't expect ordered results. So tell your developers "payback time".