Installation guide

CHAPTER 11
Adaptive Server Downgrades
An Adaptive Server that has been upgraded to 15.7 or later requires specifics tasks before it
can be downgraded.
Even if you have not used any of the new features in Adaptive Server 15.7 or later, the upgrade
process added columns to system tables. This means you must use sp_downgrade to perform
the downgrade.
The sp_downgrade procedure requires sybase_ts_ role, and you must have sa_role or
sso_role permissions. See sp_downgrade in Reference Manual: Procedures .
There are additional steps to perform if you are using encryption or replicated databases.
Note: You cannot downgrade a single database through dump and load directly from
Adaptive Server 15.7 ESD #2 to an earlier version.
Preparing to Downgrade Adaptive Server
Prepare your system before starting the downgrade.
Note: If you are downgrading to Adaptive Server 15.7 ESD #1, which supports features such
as compression and in-row LOB, skip the steps in this section.
Before you begin downgrading Adaptive Server, perform these steps for the features or
configurations you enabled in Adaptive Server 15.7 ESD #2.
• If the logical page size for your Adaptive Server is larger than 8192 bytes and you have
configured any databases to allow wide data-only-locked (DOL) rows, turn the option off:
sp_dboption @dbname, 'allow wide dol rows', false
Before you downgrade Adaptive Server, verify that no wide DOL rows exist in any table in
these databases. Adaptive Server cannot find them, and thus does not warn you about their
existence. When you then downgrade to a version earlier than 15.7 ESD #2, Adaptive
Server treats these as corrupt.
This does not occur if your logical page size is 8192 bytes or smaller.
• If you have configured any database to use either row or page compression, turn it off:
alter database @dbname set compression none
• If any database has nonzero, in-row large object (LOB) lengths, set it to zero:
alter database @dbname set inrow_lob_length = 0
• If any table is configured to use compression, turn it off:
Installation Guide 105