OpenLink Product Overview Single-Tier Drivers OpenLink Single-Tier Drivers are clientside-only ODBC and JDBC-ODBC Bridge drivers. They involve minimal installation and configuration. They are ideal for new and non-technical users, and they should be advanced before other drivers in the product portfolio. However, most Single-Tier drivers are not self-sufficient. They require the database native communications layer to connect. TDS, MySQL, PostgreSQL, and Mac OS X Oracle drivers are an exception. These drivers include bundled libraries which allow them to connect to target databases without the addition of a database native layer.