Additional downgrade steps may be necessary due to Adaptive Server 15.7 features that are not available in the Adaptive Server version to which you are downgrading.
In general, no additional steps are required when you are returning to an Adaptive Server version in which the feature was already available.
Returning to 15.0.2 ESD #3 is easier than downgrading to other versions, because this version can handle a number of error conditions that may arise as a result of downgrading.
If you return to a pre-15.0.2 ESD #3 version of Adaptive Server, no error handling is provided. Using the new features can result in inexplicable behavior, including misleading error messages and stack traces, unless you are uninstall all usages of the new features reported by sp_downgrade.
| Feature | Considerations |
|---|---|
Wide, variable-length data-only-locked (DOL) rows | You cannot downgrade versions that contain wide, variable-length DOL rows to versions that do not support the feature. Use the dol_downgrade_check function to determine if a database includes tables with wide, variable-length DOL rows. See Reference Manual: Basics for information about dol_downgrade_check. Note: If you:
|
Java in Adaptive Server |
|
sp_addserver with filter
parameter | If you have any entries in sysservers.srvnetname column
that are longer than 32 bytes, delete these entries before
downgrading, and add them back after downgrading. |
Unicode noncharacters | If you used sp_configure to enable functionality group or permissive Unicode in Adaptive Server 15.7 and also stored Unicode noncharacters (that is, u+FFFF or u+FFFE) in a database, you may see a conversion error after you downgrade to a version earlier 15.7 when Adaptive Server retrieves the data and triggers a character set conversion. To avoid such errors, search for and remove those characters from the system. |
Disabled varbinary truncation | If you used sp_configure to turn on the disable varbinary truncation configuration in Adaptive Server 15.7, the varbinary data stored in the system may have trailing zeros. When you downgrade to a version earlier than 15.7, these trailing zeros are not removed and become part of the select output. This does not affect query results involving comparisons. |
Sharable inline default | If you used sp_configure to enable the sharable inline default setting in Adaptive Server 15.7 and downgrade to a version earlier than 15.7, running the ddlgen utility to generate data-definition language can cause Adaptive Server to generate extra create default statements. You can remove such statements before using the output to create new schema. |