After you perform the basic downgrade steps, changes from the 12.5.4 upgrade still persist.
After you run installmaster on your downgraded server, any changed system stored procedures are returned to their 12.5.x status. Any new stored procedures introduced to Adaptive Server in releases subsequent to 12.5.x are not removed. Attempts to execute such stored procedures against an older binary will have unpredictable results.
The on-disk structures of stored procedures, triggers, and views may contain statement identity tokens, datatypes and object references that are not understood by the earlier Adaptive Server versions. You must drop all compiled objects that use features introduced into Adaptive Server subsequent to the release to which you are downgrading.
Should you return to a pre-12.5.0.3 version of Adaptive Server, no such soft landing is provided. Using the new features can result in inexplicable behavior, misleading error messages and stack traces.
After returning to a pre-12.5.4 binary:
When returning to 12.5.0.x or earlier, the new datatypes date, date null, time, and time null remain in systypes but you cannot use them in 12.5.0.3 and attempts to use them in 12.5.0.2 or earlier will cause a stack trace. See the special procedure for downgrading to Adaptive Server version 12.5.0.x to avoid problems with new datatypes.
sp_values is dropped and re-created when you run the 12.5.x installmaster, so any new types are eliminated from this table.
sysmessages still contains all the new error messages, but that is not a problem because they are not used.
New configuration parameters have been added in 12.5.4. When starting the previous version of the Adaptive Server, use the old .cfg configuration file. If you forget to run the 12.5.x installmaster before starting Adaptive Server, an error message displays at startup. Running the 12.5.x version of installmaster removes configuration parameters that belong to 12.5.4, by deleting sysconfigures rows for configuration parameters that do not exist in syscurconfigs. After running installmaster the error messages will no longer appear when you start the server.
Two keywords, func and function, were removed in Adaptive Server 12.5.4, making it possible to create identifiers using these names. If you did not use these as identifiers under 12.5.4, no action is needed. If you did, the parser generates a syntax error under 12.5.0.x since it interprets these words as keywords.
See “Additional steps required if you used 12.5.4 features before downgrading” for more information.
