Types of ODBC drivers
When PowerBuilder is connected to an ODBC data source, you might
see messages from the ODBC driver that include the words single-tier or
multiple-tier. These terms refer to the two types of drivers defined by
the ODBC standard.
Single-tier driver
A single-tier ODBC driver processes both ODBC functions and
SQL statements. In other words, a single-tier driver includes the data
access software required to manage the data source file and catalog
tables. An example of a single-tier ODBC driver is the Microsoft Access
driver.
Figure: Single-tier ODBC driver
Multiple-tier driver
A multiple-tier ODBC driver processes ODBC functions, but sends
SQL statements to the database engine for processing. Unlike the
single-tier driver, a multiple-tier driver does not include the data
access software required to manage the data directly.
An example of a multiple-tier ODBC driver is the SAP SQL Anywhere
driver.
Figure: Multi-tier ODBC driver
