Transaction Isolation

ActiveSpaces enforces the highest level of transaction isolation: serializable. As a result, serialization can delay database operations as transactions wait for other transactions to commit or roll back.

ActiveSpaces uses a pessimistic transaction model: blocking any operations that could violate database consistency or isolation. For example, when an operation in transaction A refers to table row R, and an operation in a second transaction B also refers to row R, then the second operation blocks until transaction A either commits or rolls back. Similarly, an operation within a transaction can block operations in non-transacted sessions.