Previously we are using Oracle 10.X version of oracle database and Currently we have been migrated to oracle 11.2 version. As a result of the database upgrade the queries which fetched the results in ascending order in older database were fetching the un-ordered rows from the migrated database.
Does the database upgrade from 10.X to 11.2 accounts for this ??
Pl post exact database versions (to 4 digits). It is a possible effect of the upgrade, as newer versions enforce SQL ANSI standards. Pl post the SQL that is returning data in a different order in 11gR2.
Pl see these MOS Docs
Order Of Data Retrieval Differs after upgrading 9i To 10g [ID 456707.1]
'Group By' Does Not Guarantee a Sort Without Order By Clause In 10g and Above [ID 345048.1]