It is very important to note that while pillars and SDB do provide much of the same data, there are some differences between them. Understanding these differences will help you decide which is more appropriate for you for each situation you encounter.
Pillar data is always generated on the master before being sent to the minion. If that data comes from another source that the master has permission to look at but not the minions, then the minions can still obtain the necessary data from the master without having to have access to that resource themselves.
SDB configuration is obtained using configuration on the system that performs the lookup. If pillar_opts is True on the master (meaning the minions receive a copy of the master's configuration as its own pillar dictionary), then SDB URIs in the master configuration will be translated on the master before being sent to the minion.
However, if it is the minion configuration that contains an...