Nilkree Likewise, setting an index up by one will move the index to the next element, regardless of the size of the element. In addition, it supports a new format, the program object, which is the functional equivalent of a load module in Partitioned Data Set Extended PDSEwith many additional capabilities. DFSORT and amazing new data processing tricks In a perfect world, data columns would be neatly aligned and easy to sort, edit vobol display. These are utility program that IBM documents in service aids or diagnosis  manuals. Articles with short description. With this utility, many different forms or logos could be stored as images, and printed mainframegyrukul needed, all using the same standard blank paper, thus eliminating the need to stock many preprinted forms, and the need for operators to stop the printer and change paper.
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We refer file as PS in Mainframe environment. In file data is organized as records. Each record is divided into set of fields. For example data related to employee file which consists of employee ID, employee name, employee Account. In this above file data is organized as multiple records each consists of 33 bytes.
Cumulative size of all fields is considered as record length. A file can be classified as fixed or variable length files. In fixed length file, size of all records must be same but in variable length file record length can be vary upon some fields which are not common. Files are further classified into 3 types. Sequential files: The records are stored in the file in the same order in which they are entered. Here, the records can be accessed only sequentially. To process any record, one has to read all its preceding records.
Further, records cannot be inserted or deleted. Sequential files are simplest to handle, they are highly inflexible as they do not facilitate insertion and deletion of records.
File opened with Extend Mode appends the writing records at the end of the file. An index sequential file is concep- tually made up of two files, a data file and an index file. Though the records are stored in the order in which they are entered, a sorted index is maintained which relates the key value to the position of the record in the file and hence provides a way to access the records both sequentially and randomly. This is identified as relative record number.
The access method stores and retrieves a record, based on its relative record number. Records can be accessed as sequentially or randomly or dynamically. This relative files faster access compared to other 2 organizations.
But if some of the intermediate records are missing, they occupy space. For any kind of operation against the file inside the program, make sure you use Logical name only i. In JCL Instead, the usual practice is to group a number of consecutive records to form what is known as a physical record or a block the number of records in a block is termed as the blocking factor. There are two advantages of blocking logical records into a physical record.
For example to search for a record file has to read sequentially, if each record is reading from Disk at a time which is time consu- ming in order to speed the access of records, a couple records are read from DISK and keep in intermediate storage called buffer. For sequential access allocation of large block sizes faster the access. For random access a small block size faster the access of records.
For instance. After performing each operation on file it is good practice to check the file status code whether the operation was successful or not, based on this appropriate action is performed. When it is omitted, the compiler assumes that records are not blocked.
MainFrames Interview Questions
In this, functionalities are divided into modules. It is a logical way of programming and helps us to write the code logically. In this, first objects are identified and then the functions and procedures are written. It is a natural way of programming.