DataAccess.getUpgradeOptimizedConnection() was originally added by
LPS-26983 to solve some deadlock issue for SQL Server which later got applied to Sybase too.
However no one can remember what the original issue was, and there is no way to reproduce it now. The implementation code does not really make sense on the current codebase. The original issues were most likely caused due to we used multiple jdbc connections in the same upgrade process, which fooled the DB to think there was a concurrent accessing and leading to deadlocks. Since we have been globally enforced single jdbc connection upgrade, the issue is most likely not going to happen anymore.
To keep upgrade frame simple and clean, we remove the support and usage of DataAccess.getUpgradeOptimizedConnection(). In case any upgrade deadlock issues are detected in the future, we will solve them again in proper ways.