Downgrading from Adaptive Server 15.7 SP100

Use sp_downgrade to downgrade Adaptive Server 15.7 SP100 to an earlier version.

Prerequisites

Note: Do not use these steps if you are downgrading from Adaptive Server version 15.7 SP100 to version 15.7, 15.7 ESD #1, 15.7 ESD #2, ESD #3, or ESD #4. Instead, see Downgrading to an Earlier Version of Adaptive Server 15.7.

Save the current auditing settings for the 15.7 SP100 Adaptive Server by saving the output of the sp_displayaudit system procedure in all system and user databases where any auditing options have been turned on:
```
1> sp_displayaudit
2> go
```
Back up all of your databases and the $SYBASE release area.

Task

Downgrade from Adaptive Server 15.7 SP100 to an Adaptive Server 15.5. Downgrading to versions of Adaptive Server earlier than 15.5 is not supported.

Start the 15.7 SP100 server in single-user mode using dataserver -m to guarantee that no other user can access Adaptive Server while you are going through the downgrade steps. See the Utility Guide for more details on starting the server in single-user mode.
Make sure Adaptive Server 15.7 SP100 is prepared for downgrade by executing this command from the master database:
```
sp_downgrade 'prepare', @toversion='version'
```
The format for the value of version does not need periods, so these variations are both valid:"15.5", "155". The version you enter should be the Adaptive Server version to which you want to downgrade.

sp_downgrade 'prepare' validates the readiness of Adaptive Server 15.7 SP100 for downgrade. It may print messages regarding manual changes that are required before the downgrade can be completed. Repeat this step, correcting any errors reported, and make sure you understand the implications of all warnings before proceeding.
Execute the following, where version is the same number you used in the previous step:
sp_downgrade 'downgrade', @toversion='version', @override=1
Once this procedure completes successfully, there can be no more activity on the 15.7 SP100 server. Run checkpoint and immediately issue the shutdown command.

Note: Since Adaptive Server 15.7 SP100 transaction logs may contain data that older server versions cannot interpret correctly, all transactions in all databases must be completed to prevent the older server from recovering any transactions. To ensure that all transactions are completed, issue the normal shutdown command, and not the shutdown with nowait command, after running sp_downgrade.
Copy the RUN_SERVER file to the release area for the version you are downgrading to. Modify the file to use the dataserver binary of the version to which you are downgrading, using -e, -c, and -M option point to the old server.
For example, if you are downgrading to 15.5, change 15.7-related information to 15.5-related information. From the SYBASE directory, issue:
```
/work_dirs/sybase/ase155/ASE-15_5/bin/dataserver\
    -s old_server_name\
    -d downgraded_master_device\
    -e old_server_log_file\
    -c old_server_config_file\
    -M /work_dirs/sybase/ase155\
```
Restart the old server using the modified RUN_SERVER file. Ensure that the environment variable points to the old server release, such as $SYBASE, $SYBASE_ASE, or $SYBASE_OCS.
Run any post-downgrade scripts that may be applicable to your site, including installmaster and instmsgs.ebf.

If you have not used any 15.7 SP100 functionality, this completes the primary downgrade process.