Reserved words are pieces of SQL syntax that have special meaning when used as part of a command.
Transact-SQL does not allow words that are part of command syntax to be used as identifiers, unless they are enclosed in quotation marks, as explained in “Using quoted identifiers”. If you are upgrading Adaptive Server, and the identifiers in your user databases match new reserved words, errors can result when you run queries, stored procedures, or applications that use these identifiers.
WARNING! If a user database name is a reserved word, upgrade fails when it tries to upgrade the database. You must use sp_renamedb to change the name of any user database that is a reserved word before performing the upgrade.
Conflicts between object names do not prevent the upgrade process from completing. However, applications that refer to conflicting object names may not work after the upgrade. Rename all objects that use reserved words.
As part of the pre-upgrade process, sqlupgrade can perform the reserved word check for you. See the Reference Manual for a complete list of reserved words.
If you change an object name, change applications and stored procedures that refer to that object.