The INREC control statements allow users to reformat an input record before processing. The user can Define the parts of an input record to be included in the reformatted input record. Denote the order they are to appear. How they are to be aligned. Insert blanks and binary zeros as separators before, between, and after
The FIND DURATION function is used to calculate duration between: The FIND-DURATION function returns an integer in the form of complete units of the specified duration. Any rounding is done downwards. The calculation of durations includes microseconds. The function type is integer. The function result is a nine-digit integer. If the function result is larger
Find Duration – Add – Subtract – MOD Duration using COBOL Read More »
The collection of records belonging to the same entity is known as File. These records are stored permanently. File handling helps to organize these records in an ascending/descending order. It makes searching, accessing these records more easily and efficiently. The records are generally stored on a magnetic tape or a disk. Advantages of File Handling Disadvantages of File
FILE ALLOCATION is a key concept in COBOL programming. A file is a collection of data related to a set of entities and typically exists on a magnetic tape or a disk. We refer file as PS in the Mainframe environment. In File, data is organized as records. Each record is divided into fields that
Any I-O operations on a file, there are chances that it may fail. We need to have COBOL FIle Error Handling. COBOL itself does not automatically take corrective action, we have to choose whether our program should continue running after an error or not. The severity of the error has to be defined in the
The ROUNDED option used to round the fraction result of the compute statement exceeds the length of the target data item fractional places. After decimal point alignment, the number of fraction places in arithmetic operation is compared with the number of fraction places of result identifier. If the size of the fractional result exceeds the
GDG Stands for ‘Generation data group’ & is used to catalog a group of datasets that have common and similar data formats, and these datasets can be referenced by relative generation and version number. It is mostly used to take periodic backups of critical data for future reference. All datasets within GDG share the same
COUNT function can be used to print messages containing the count of records in a data set. It can also be used to subtract a value from the count or add a value to the count, to create an output data set containing text and the count, or to set RC=12, RC=8, RC=4, or RC=0
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ACCEPT parameter is an OUTFIL option that limit the number of input records accepted for OUTFIL processing. A record is “accepted” if it is not deleted by STARTREC, ENDREC, SAMPLE, INCLUDE or OMIT processing. ACCEPT makes it easy to limit the number of OUTFIL input records selected for processing. After n OUTFIL input records have
IFTRAIL parameter is used to update count and total values in an existing trailer (last) record to reflect the actual data records in the output data set using COUNT and TOTAL features of TRAILER1. TRAILER1 lets you build a new trailer record but IFTRAIL lets you update an existing trailer record. When you specify IFTRAIL
Figurative constants are reserved words that name and refer to specific constant values. These can be easily used by writing the word itself instead of the value. The figurative constants supported by COBOL are: ZERO, ZEROS, ZEROES SPACE, SPACES HIGH-VALUE, HIGH-VALUES LOW-VALUE, LOW-VALUES QUOTE, QUOTES ALL literal – which means fill the field with ALL
Mainframe developers and support engineers quickly learn one painful truth: if you work long enough with COBOL, JCL, and z/OS, you will face S0C abends. These system completion codes (like S0C1, S0C4, S0C5, and S0C7) indicate serious program or data problems that cause your job to terminate abnormally. Two types of abend codes User abends – format Uhhhh (e.g., U4095),
Database NORMALIZATION is used to reduce data redundancy and eliminate undesirable characteristics like Database Anomalies (Update anomaly, Insertion anomaly, Deletion anomaly). This also divides larger tables into smaller tables and links them using relationships and follows simple data structure design rules to make the data easy to understand, maintain and query. Rule of Clarity –
By default, cursors are moved by 1 row at a time in the result table in sequential order starting from the first row. To remove this limitation SCROLL clause is used to indicate whether the cursor moves sequentially through the result table or can move randomly through the result table. You can declare row-positioned or
TIME parameter specifies the maximum amount of time that step may use the processor or to find out through messages how much processor time a step used. It is an optional Keyword parameter & this is important to save MIPS(Million Instructions Per Second). This can be used either in JOB or in STEP or in
IF THEN ELSE ENDIF construct is used to conditionally execute job steps within a job. A job step execution can be controlled based on the return code of the previous step(s) using the COND parameter and IF-THEN-ELSE-ENDIF construct. The IF statement is always followed by a relational expression and a THEN clause. Optionally, an ELSE
COND parameter is used to test return codes from previous job steps and determine whether to bypass or execute specified job steps. Return code is set based on the status of execution of a job. The return code can be a number between 0 (successful execution) to 4095 (non-zero shows error condition). 0 = Normal
Space ABEND is among the most common JCL failures developers encounter in production and batch processing. These abends indicate an out‑of‑space condition on DASD volumes and are typically raised when a dataset cannot be extended or allocated with the requested amount of space. There are three types of Space ABEND as mentioned below. SB37: There
SQL Error Code is used on a day to day basis for the diagnosis of programming failures as a result of SQL calls by DB2 computer programs. An important feature of DB2 programs is the error processing. The error diagnostic containing the SQL Error Code are held in the field SQLCODE within the DB2 SQLCA block. This Instant
The OPTION control statement allows you to override some of the options available at installation time (such as EQUALS and CHECK) and to supply other optional information (such as DYNALLOC, COPY, and SKIPREC). Some of the options available on the OPTION statement are also available on the SORT or MERGE statement (such as FILSZ and
The LISTCAT command is used to list and view the attributes and characteristics like space allocation information, password and security-related information, usage characteristics, creation, and expiration date, etc of VSAM or non-VSAM entries. It stands for LISTing of CATalog entry. The LISTCAT line command allows access to IDCAMS and displays the tablespace or indexspace space
LISTCAT use in retrieving GDG or VSAM Information Read More »
You can use one of the numeric test capabilities of the INCLUDE OMIT Numeric test statement to collect the records you want. You can use one of the numeric test capabilities of the INCLUDE OMIT Alphanumeric test statement to collect the records you want. You can use the INCLUDE OMIT Substring Comparison statement in conjunction
You can use the INCLUDE OMIT Substring Comparison statement in conjunction with other options to select/omit the number of records to be processed, which can reduce processor and data transfer time. There are two types of INCLUDE OMIT Substring Comparison tests: Find a constant within a field value: For example, search the value in a
SQL Query optimization is a process of writing optimized SQL queries to improve database performance. It is one of the factors that affect application performance. When working with large-scale data, even the most minor change can have a dramatic impact on performance. Top 10 ways to improve performance Indexing: Proper indexing ensures optimal access to
The DB2 Predicates affect how DB2 selects the access path for the statement. Predicates are found in the WHERE, HAVING, or ON clauses of SQL statements; they describe attributes of data. Most DB2 predicates are based on the columns of a table. They either qualify rows (through an index) or reject rows (returned by a
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