Perform these steps only when you are downgrading to 12.5.0.x. Returning to 12.5.0.3 is preferable, because these versions can handle a number of error conditions that may arise as a result of downgrading. Older version of Adaptive Server cannot handle these situations and results are unpredictable.
Although it is not necessary to restore systypes and syscharsets to their previous state, Sybase provides the store procedure sp_twelve_five_one to do so.
After returning to Adaptive Server version 12.5.0.x, remove the new datatypes from systypes and syscharsets and return these tables to their 12.5.0.x state by performing the following steps:
Enable updates to system tables:
sp_configure "allow updates", 1
Remove the 12.5.4 datatypes:
sp_twelve_five_one "remove"
Disable updates to system tables:
sp_configure "allow updates", 0
This procedure also marks all procedural objects for recompiling, to insure that the pre-12.5.4 Adaptive Server does not encounter 12.5.4 objects or datatypes.
