# Concurrency Control and eXtremeDB Transaction Managers

> As explained in the Fundamental Concepts, eXtremeDB manages multi-thread and multi-process contention for database data through the use of transaction blocking; and provides three different transaction managers that handle concurrent access to data according to either optimistic or pessimistic strategies.

> The eXtremeDB transaction managers support three Transaction Isolation levels that can influence performance for concurrent database access. And, in some cases, Transaction Priorities or the Transaction Scheduling policy can be adjusted to affect how database transactions are managed by the transaction managers.

> The APIs and structures for managing concurrency are specific to the programming language used. Please use the links below to view detailed explanations and examples for your development environment:

> C | Concurrency and Transaction management in C
> C++ | Concurrency and Transaction management in C++
> Java | Concurrency and Transaction management in Java
> Python | Concurrency and Transaction management in Python
> C# | Concurrency and Transaction management in C#