I have an application which has been validated on an Oracle 11.2 database. A client has asked me whether they can use Oracle 12c instead as that is what their IT department would prefer. Is there an official list anywhere of incompatibilities between Oracle 11 and 12? Is there anything I need to look out for?


I was looking through the Oracle database and found the following (conflicting) information:

Existing applications running in a new release of Oracle Database function the same as they did in earlier releases and achieve the same, or enhanced, performance. You are not required to modify existing applications that do not use features available in the new Oracle Database release.

Followed by:

There might be compatibility issues between different releases of Oracle Database that could affect your applications. These compatibility issues result from differences in Oracle Database in various releases. Also, in each new release of Oracle Database, new Oracle reserved words might be added, changes might be made to initialization parameters, and changes might be made to the data dictionary.

  • The information you require is in the change logs and upgrade documents. However there is no guarantee that there won't be any surprises. When you say "an application", do you mean purchased from a vendor or in-house? If the first, ask the vendor if it's supported on 12c. If the second, you will need to test it and validate it yourself. – Phil Sumner Aug 21 '14 at 9:20
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    The functionality in all likelihood will be the same. What can cause nasty surprises is stuff like plans changing which can lead to unexpected performance glitches - i.e. queries which performed satisfactorily under version x suddenly become sluggish under version x + 1. Having said that, one can also obtain gains. – Vérace Aug 21 '14 at 9:35
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    This is probably true with every piece of software, else you wouldn't need new versions. There are incompatibilities, new features and feature removal. Each version of Oracle usually has 'New Features Guide' which lists new features, changes etc. That would be a good starting point. Like Phil says, there is no substitute for testing. – Raj Aug 21 '14 at 11:32
  • docs.oracle.com/database/121/UPGRD/deprecated.htm#UPGRD60000 for a list of things that got desupported. You'll never know if you're good to go on 12c without testing (and that's nothing specific to 12c or Oracle). – Mat Aug 21 '14 at 12:16

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