ACD200 Exam Dumps - Appian Certified Senior Developer

The @Version annotation is used to avoid the collision of data from an application when more than one user is editing the same record in a database. The @Version annotation enables optimistic locking, which is a mechanism to detect and prevent concurrent updates on the same record. Optimistic locking assumes that multiple transactions can complete without affecting each other, and that therefore transactions do not need to lock data resources until they are ready to commit. However, if a transaction tries to commit changes to a record that has been modified by another transaction since it was last read, an OptimisticLockException is thrown and the transaction is rolled back. The @Version annotation can be applied to a field or property of a CDT that stores a numeric value. This value is used as a version number that is automatically incremented by Appian every time the record is updated. References: Does Appian support @Version JPA Annotation?, JPA - Optimistic Locking and Use of @Version annotation

 The minimum privilege the end user should have to execute a web API is Viewer. A web API is an Appian object that exposes data and services to outside systems through an HTTP endpoint. A web API can be configured with different security role maps that control which users can see or modify it and its properties. A user must have at least Viewer permissions to a web API in order to execute it. Viewer permissions allow the user to view and run the web API, but not to edit or delete it. References: Web APIs, Web API Security

 The best way to restrict the uploading of documents without extensions at the environment level is to enable the File Upload > Block files without an extension option under the Administration Console. This option will prevent users from uploading files that do not have a valid file extension, such as .docx, .pdf, or .png. This can help to avoid security risks and compatibility issues with unsupported file types. Therefore, the correct answer is A.

References:

• [File Upload Settings]
• [File Extensions]

An index is a data structure that allows for faster retrieval of data from a table based on one or more columns. Indexes increase the performance of read operations, such as select queries, by reducing the number of records that need to be scanned. However, indexes decrease the performance of write operations, such as insert, update, and delete queries, by requiring additional work to maintain the index structure and ensure its consistency with the table data. Therefore, indexes should be used judiciously and only on columns that are frequently used in queries and have high selectivity (i.e., low number of duplicate values). 

The lowest permission required on the data store in order to query, write, and delete data is Viewer. This is because the data store permissions only control the ability to view and modify the data store object in Appian Designer, not the actual data in the database. To query, write, and delete data, the user needs to have the appropriate SQL permissions on the database tables or views that are mapped to the data store entities. References: Data Store Permissions

The likely cause for a task on a newly-launched process in Production being slow to respond to user input is having too many SAIL components on the task. SAIL components are the UI elements that make up an interface in Appian. Having too many SAIL components on a task can negatively impact the performance and user experience of the interface, as it increases the rendering time and complexity of the interface. It can also cause browser compatibility issues or memory leaks. It is recommended to limit the number of SAIL components on a task to less than 100, and to use grids, collapsible layouts, or tabs to organize and display data efficiently. References: SAIL Components Overview, SAIL Performance Tips