A common configuration mistake is to configure externally managed transactions where datasource and tx manager don't match, i.e. the tx manager doesn't manage the datasource. This leads to the situation that the datasource is used in autocommit mode and therefore creates database inconsistencies. This is particularly common in Spring Boot setups, where people do not actively choose to configure transaction integration and therefore are often not aware at all of this problem.

AT:

• Document that datasource and tx manager must be configured consistently
• Highlight this especially in the Spring Boot docs