IBM AS400 Intermediate Level Questions
Q1. What is IBM AS400?
IBM AS400, also known as IBM iSeries or IBM System i, is a midrange server platform developed by IBM, designed for small to mid-sized businesses. It integrates hardware, software, and storage resources to provide a comprehensive business computing solution.
Q2. What are some key features of IBM AS400?
IBM AS400 is known for its robustness, reliability, and scalability. Some key features include:
- Integrated database management system (DB2)
- High availability and disaster recovery capabilities
- Security features such as user authentication and access control
- Built-in support for multiple programming languages like RPG, COBOL, and Java
- Easy-to-use management interfaces for system administration
Q3. How does IBM AS400 handle data storage and management?
IBM AS400 uses a hierarchical file system called the Integrated File System (IFS) to organize and manage data. It also includes a relational database management system (DB2) for structured data storage, providing features such as journaling, commitment control, and SQL support for data manipulation.
Q4. What programming languages are commonly used on IBM AS400?
IBM AS400 supports a variety of programming languages, including RPG (Report Program Generator), COBOL, Java, CL (Control Language), and SQL (Structured Query Language). Each language has its own strengths and is used for different types of applications and development tasks.
Q5. How does IBM AS400 ensure system availability and reliability?
IBM AS400 provides built-in features for high availability and disaster recovery, such as clustering, mirroring, and journaling. These features help minimize downtime and data loss by ensuring that critical business operations can continue even in the event of hardware failures or system errors.
Q6. Can you explain the role of CL programming on IBM AS400?
CL (Control Language) is a scripting language used for system administration and automation tasks on IBM AS400. CL programs, known as CL programs, can be used to perform various tasks such as starting and stopping subsystems, managing job queues, and executing commands.
Q7. How does IBM AS400 support integration with other systems and applications?
IBM AS400 provides various integration options, including support for web services, APIs, and middleware such as IBM WebSphere. It also includes built-in connectivity features such as TCP/IP networking, FTP (File Transfer Protocol), and ODBC (Open Database Connectivity) for accessing and exchanging data with external systems.
Q8. What are some best practices for system administration on IBM AS400?
Some best practices for system administration on IBM AS400 include:
- Regular system backups and data archiving
- Monitoring system performance and resource usage
- Implementing security policies and access controls
- Keeping the system software up-to-date with patches and updates
- Implementing disaster recovery plans and testing them regularly.
Q9. What role does the Integrated File System (IFS) play in IBM AS400?
The Integrated File System (IFS) in IBM AS400 provides a single, unified interface for accessing and managing both traditional database files and stream files, such as documents, images, and program objects. It allows users to work with a variety of data types using standard file system operations.
Q10. How does IBM AS400 handle batch processing?
IBM AS400 supports batch processing through its job scheduling and management capabilities. Batch jobs can be scheduled to run at specific times or triggered by events, and administrators can prioritize and monitor job queues to ensure efficient resource utilization.
Q11. What is commitment control in IBM AS400, and why is it important?
Commitment control is a feature of the DB2 database management system on IBM AS400 that ensures data integrity by managing transactions and enforcing ACID (Atomicity, Consistency, Isolation, Durability) properties. It helps maintain data consistency by ensuring that changes made by a transaction are either committed or rolled back as a single unit.
Q12. Can you explain the concept of libraries in IBM AS400?
Libraries in IBM AS400 are containers for organizing and storing objects such as programs, files, and documents. They provide a logical grouping mechanism to manage and control access to resources within the system. Libraries can be shared among multiple users and applications, facilitating collaboration and resource sharing.
Q13. How does IBM AS400 support high availability and disaster recovery?
IBM AS400 offers various features for high availability and disaster recovery, including:
- Hardware redundancy and fault-tolerant configurations
- Data replication and mirroring for continuous backup and failover
- Journaling and commitment control to ensure data integrity
- Automated backup and recovery processes
- Integration with third-party disaster recovery solutions
Q14. What is Query/400, and how is it used in IBM AS400?
Query/400 is a query and reporting tool provided with IBM AS400 for creating and executing ad-hoc queries against the system's relational database (DB2). It allows users to extract and analyze data from multiple tables using a simple, menu-driven interface without requiring advanced SQL knowledge.
Q15. How does IBM AS400 support security and access control?
IBM AS400 provides robust security features, including user authentication, object-level permissions, and role-based access control. Administrators can define security policies to restrict access to sensitive data and resources, audit user activities, and enforce compliance with regulatory requirements.
Q16. What is the significance of job queues in IBM AS400?
Job queues in IBM AS400 are used to manage and prioritize batch processing jobs. Jobs are submitted to specific queues based on their priority and resource requirements, and the system automatically schedules and executes them based on available resources and configured priorities.
Q17. How does IBM AS400 support communication with external systems?
IBM AS400 supports various communication protocols and interfaces for connecting with external systems, including:
- TCP/IP networking for communication over IP-based networks
- FTP (File Transfer Protocol) for transferring files to and from remote systems
- ODBC (Open Database Connectivity) for accessing and querying external databases
- Web services and APIs for integrating with web-based applications and services
Q18. What are some common maintenance tasks performed on IBM AS400?
Common maintenance tasks on IBM AS400 include:
- Installing software updates and patches
- Monitoring system performance and resource usage
- Optimizing database performance and storage utilization
- Managing user accounts and permissions
- Backing up and restoring data
- Performing routine system checks and diagnostics
Q19. How does IBM AS400 support system monitoring and performance tuning?
IBM AS400 provides built-in monitoring tools and performance analysis utilities for tracking system resource usage, identifying bottlenecks, and optimizing performance. Administrators can use tools such as Performance Navigator, Job Watcher, and System Monitors to monitor CPU, memory, disk, and network utilization and make adjustments as needed.
Q20. Can you explain the role of subsystems in IBM AS400?
Subsystems in IBM AS400 are logical groupings of related jobs and resources that facilitate system management and workload isolation. Each subsystem is responsible for specific tasks or functions, such as batch processing, interactive user sessions, or database operations. Subsystems help organize and prioritize workload, allocate resources efficiently, and simplify system administration.
IBM AS400 Advance Level Questions
1. What is library list in AS400 and how does it affect program execution?
The library list in AS400 is a system object that determines the order in which libraries are searched when an object is referenced. It affects program execution by directing where the system looks for program, file, or other object references, thereby influencing the loading and running of programs.
2. Explain the purpose and usage of data queues in AS400.
Data queues in AS400 are used for communication between different jobs or processes, allowing them to pass information in a first-in, first-out (FIFO) sequence. They are particularly useful for asynchronous data processing and can help in managing workloads by decoupling the processes that produce data from those that consume it.
3. Describe the difference between non-join logical files and join logical files in AS400.
Non-join logical files are based on a single physical file and can include select/omit criteria, redefine record formats, or change the sequence of records. Join logical files, however, are based on joining two or more physical files, creating a single logical view that combines their data, useful for queries that need to access multiple related tables.
4. How do you handle error logging in AS400 applications?
Error logging in AS400 applications is commonly managed through the use of service programs that encapsulate the error handling routines. These programs typically write error information to a physical file, send messages to a message queue, or log to the system log depending on the severity and type of error.
5. What are the benefits of using SQL in AS400 environment?
Using SQL in an AS400 environment provides enhanced data manipulation capabilities, better integration with other SQL-based systems, more complex querying abilities, and a standard language for database interaction that is widely used and understood in the industry.
6. Can you explain commitment control in AS400? How is it used in transaction processing
Commitment control in AS400 is a function that ensures all changes in a transaction are completed before the changes are permanently applied. It is used in transaction processing to ensure data integrity, allowing all operations within the transaction to be committed or rolled back together, thus maintaining database consistency.
7. What is the role of the Integrated File System (IFS) in AS400?
The Integrated File System (IFS) in AS400 provides a hierarchical file system view of all data on the server, integrating traditional AS400 data with stream input/output data into a single system. This allows users and applications to use familiar file operations on all types of data, and supports a variety of network file protocols.
8. How do you optimize SQL queries in AS400?
Optimizing SQL queries in AS400 involves several strategies such as using indexes effectively, avoiding unnecessary columns in the SELECT clause, minimizing the number of JOINs, using WHERE clauses to filter rows early, and analyzing the query execution plan to identify and correct performance bottlenecks.
9. Describe the use of subfiles in AS400 for screen design.
Subfiles in AS400 are used for handling lists of data on display screens. They allow for the dynamic display of a scrollable list of records, making it easier to manage large volumes of data in an interactive application. Subfiles separate the display information from the program logic, simplifying screen design and management.
10. What is job scheduling in AS400 and how can it be managed?
Job scheduling in AS400 refers to the ability to set up jobs to be run at specific times or under specific conditions. It can be managed through the Job Scheduler subsystem, third-party scheduling tools, or simple job queues that prioritize and manage job execution. Effective job scheduling helps in automating repetitive tasks and optimizing system resources.