Using the ADABAS Database in the NATURAL Language

ADABAS Structure

ADABAS uses a data model based on records organized into files, where each file contains multiple records, and each record has multiple fields. The main components of ADABAS include:

• Files: Equivalent to tables in relational databases.
• Fields: Correspond to columns within a file.
• Descriptors: Used for indexing and query optimization.
• Superdescriptors and Subdescriptors: Ways to combine fields to create composite indexes.

NATURAL Language and ADABAS

The NATURAL language was developed to facilitate data access and manipulation in ADABAS, using high-level commands. Some of the key commands include:

1. Data Retrieval

The FIND command allows searching for records using an efficient selection criterion:

FIND EMPLOYEES WITH NAME = 'JOHN'
  DISPLAY ID NAME POSITION SALARY
END-FIND        

This command retrieves employees named "JOHN" and displays their information.

2. Sequential Reading

To iterate through all records in a file, we use READ:

READ EMPLOYEES BY ID
  DISPLAY ID NAME SALARY
END-READ        

Here, records are read sequentially, ordered by the ID field.

3. Updating Records

The UPDATE command allows modifying existing records:

FIND EMPLOYEES WITH ID = 12345
  UPDATE
    SALARY = SALARY * 1.10
  END TRANSACTION
END-FIND        

This example increases the salary of the employee with ID 12345, referenced in the FIND statement, by 10%.

4. Inserting New Records

To insert new records, we use STORE:

STORE RECORD IN EMPLOYEES
  ID := 67890
  NAME := 'MARY'
  POSITION := 'ANALYST'
  SALARY := 5000
END TRANSACTION        

5. Deleting Records

Record removal in ADABAS is done with DELETE:

FIND EMPLOYEES WITH ID = 67890
  DELETE RECORD
  END TRANSACTION
END-FIND        

This command removes the employee record with ID 67890.

Best Practices

To ensure optimized performance and avoid concurrency issues, it is important to follow some best practices:

1. Efficient use of FIND and READ: Whenever possible, use FIND with descriptors to improve performance.
2. Avoid unnecessary updates: UPDATE should be used cautiously to minimize database locks.
3. Proper use of buffers: ADABAS allows configuring read buffers to optimize access to large data volumes.
4. Monitoring and tuning: ADABAS performance analysis tools can help identify bottlenecks and optimize queries.

Final Thoughts

When used with the NATURAL language, ADABAS provides a robust and efficient platform for data manipulation in legacy systems. Deep knowledge of commands and best practices is essential to ensure optimized performance and effective system maintenance.