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 […]
INREC control statement use in SORT Read More »
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 Handling Verbs in COBOL Programs Read More »
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
FILE ALLOCATION – COBOL File Handling Read More »
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
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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
ROUNDED and ON SIZE ERROR use in COBOL Read More »
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
GDG – Generation Data Groups operations in JCL Read More »
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
COUNT Function: Count number of records in a file Read More »
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
ACCEPT n records with OUTFIL SORT utility Read More »
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
IFTRAIL – Trailer record update using SORT Read More »
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
Figurative constants use in COBOL Programs Read More »
Two types of abend codes, user abends and system abends (S0C Abends). User abends format is Unnnn, where nnnn is a decimal user abend code. System abends follow the format of Snnn, where nnn is a hexadecimal abend code. S0C Abends are the abnormal ending of Job & when it happens a message from the JCL or Fault Analyzer will
S0C Abends – S0C1 S0C4 S0C5 S0C7 Read More »
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 –
Database Normalization with Examples Read More »
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
SCROLL vs NO SCROLL Cursors in DB2 Read More »
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
TIME parameter use & S322 Abend in JCL Read More »
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
IF THEN ELSE ENDIF construct use in JCL Read More »
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
COND Parameter – Evaluate Return Code in JCL Read More »
Space ABEND generally occurs when your system encounters the end of volume condition occurs. There are three types of Space ABEND as mentioned below. SB37: There are not enough space or no more extents available on the current volume. The system gave all the primary space and as much secondary space as it could. Disk
Space ABEND – SB37, SD37, SE37 & Resolution Read More »
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
SQL Error Code with Explanation & Resolution Read More »
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
OPTION control statement in SORT JCL Read More »
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 usage
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
INCLUDE OMIT Numeric Test Alphanumeric Test Read More »
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
INCLUDE OMIT Substring Comparison using SORT Read More »
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
SQL Query Optimization: Tips & Tricks Read More »
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
DB2 Predicates : Performance Tuning of DB2 Queries Read More »
