Additional Considerations for New Features Used

Additional downgrade steps may be necessary due to Adaptive Server 15.7 or later features that are unavailable 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.

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: Building Blocks. If you: Disable the allow wide dol rows database option before performing a database or transaction log dump Load these database dumps onto an earlier version of Adaptive Server Data returned from queries on the wide rows may be incorrect, or queries might fail because the earlier version of Adaptive Server perceives the data rows as corrupt.
Java in Adaptive Server	Versions of Adaptive Server earlier than 15.0.3 ignore the enable pci parameter; you can remove it. The `sybpcidb` database is not used by Adaptive Server versions earlier than 15.0.3, and may be dropped.
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 SP100, 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 than 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 SP100, 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 may cause Adaptive Server to generate extra create default statements. You can remove such statements before using the output to create new schema.