Confluence and your database must be configured to use the same character set.
Confluence uses the UTF-8 character set encoding, so your database must also be configured to use UTF-8 (or the same encoding as UTF-8, for example, Al32utf8 encoding used in Oracle).
When you install confluence for the first time, you need to consider several of the following location configurations using different character sets:
When you create a database.
When you use the JDBC string to connect to the database when you configure the connection string, or the data source you are using (if you are using the simple configuration mode when you install Confluence, the Setup Wizard will automatically help you configure).
The Confluence Installation Wizard will check your character set when it is installed, and if there is a problem, the installation wizard will pop you a warning message. This will ensure that you do not have problems in the subsequent configuration and operation, relative to the late adjustment, it is now easier to solve the problem, when you have data stored in the database when the character set adjustment is more troublesome.
The guidelines for how to make character set adjustments for each database supported by confluence are as follows: When you create a database, refer to the following guidelines.
Database Setup for PostgreSQL
Database Setup for MySQL
Database Setup for SQL Server
Database Setup for Oracle
Https://www.cwiki.us/display/CONFLUENCEWIKI/Configuring+Database+Character+Encoding
Confluence 6 New Installation configuration database character Set encoding