Access Path and Types of Access Paths in AS400

Access Path and Types of Access Paths in AS400

Access path

A file contains the access path that describes how the records are retrieved from the file.

Types of Access Path

There are two types of access paths on that basis records are retrieved.

Arrival sequence (Non-keyed) access path

Keyed-sequence access path

Arrival sequence (Non-keyed) access path

The arrival sequence access path retrieves the record in the order the records are stored in the file.

Keyed-sequence access path

The keyed-sequence access path retrieves the record in the order of the key field defined in the file. The keyed sequence access path gets updated whenever any record gets added, deleted or the value of the key field gets changed.

Example of Keyed-Sequence Access Path

Create a physical file FILE1 as below

A          R RFILE1                    
A            EMPID          2  0    
A            EMPNAME       20

Create a logical file FILE1LF as below

A                                      UNIQUE
A          R RDILE1                    PFILE(FILE1)
A            EMPID
A            EMPNAME
A          K EMPID

The logical file FILE1LF based on PF FILE1 is a keyed sequence access path having key field EMPID and having Unique records