Final answer:
In client/server environments, application logic is split across clients and servers, typically with presentation logic on clients and business and data access logic on servers. Key data management security features include authentication, encryption, and backups. Shared locks enable simultaneous reads by multiple transactions, whereas exclusive locks restrict all access during a transaction.
Step-by-step explanation:
Distribution of Application Logic in Client/Server Environments
In a client/server environment, the distribution of application logic components across clients and servers can vary. Typically, the logic is divided into three categories: presentation logic, business logic, and data access logic. The presentation logic is generally found on the client side, providing the user interface. Business logic, which includes the rules of the application, can be situated on either the client or the server, though modern applications tend to place it more on the server side for better scalability and maintenance. Data access logic is almost exclusively found on the server side, managing database interactions.
Important Security Features for Data Management
The most important security features for data management software include authentication, authorization, encryption, audit trails, and backup & recovery mechanisms. These features ensure that access to data is controlled and monitored, data is protected both in transit and at rest, and any changes to data are tracked and can be restored inecessary.
Threats to Data Security
Threats to data security that must be addressed in a comprehensive data security plan include unauthorized access, data breaches, data corruption, data loss, and insider threats. Measures must be in place to protect against these threats such as robust user access controls, network security mechanisms, regular data backups, and employee training programs.
Difference Between Shared and Exclusive Locks
The difference between shared locks and exclusive locks is primarily about concurrency control in databases. Shared locks allow multiple transactions to read a database resource simultaneously but prevent any transaction from writing to it while the lock is active. In contrast, an exclusive lock prevents other transactions from both reading and writing to the resource until the lock-holder's transaction is complete, ensuring data integrity during updates.