Packages are DB2 database objects which hold the executable forms of SQLs which are used in COBOL-DB2 programs. The packages are stored in a catalog table and contain the strategy/tables/columns/predicate associated with the SQL statements.If there is a DB2 table ORDERS_TEST in test environment and ORDERS_PROD in production environment, then ... Read More

When the COBOL-DB2 source code is given as an input in the pre-compilation stage, we get 2 important components — DBRM and modified source code.In modified source code, the SQL statements are replaced by COBOL calls and the DBRM contains all the SQL statements which are present in the COBOL-DB2 ... Read More

Problem: What is INTEGRITY in a DB2? Explain DOMAIN, ENTITY and REFERENTIAL integrity with the help of an example in ORDERS table.SolutionThe integrity refers to the accuracy, consistency and correctness of data present in the DB2 database. Data integrity is imposed during the database design to make sure that data ... Read More

The duplicate INVOICE_ID in ORDERS DB2 table can be found by using a combination of GROUP BY with HAVING clause and COUNT function. The GROUP BY will enable us to group the result invoice wise and COUNT function will enable us to count the number of occurrences in each group. ... Read More

Problem: Write a query on TRANSACTIONS DB2 table to list down the number of orders (ORDER_ID) assigned to a particular transaction (TRANSACTION_ID).SolutionWe can use the below query to find out the number of orders assigned to a particular transaction id on TRANSACTIONS DB2 table.ExampleSELECT TRANSACTION_ID, COUNT(ORDER_ID) FROM TRANSACTIONS    GROUP ... Read More

When we get -551 in the SQLCODE then there is some privilege level issue. It signifies that the user does not have access to the database/tablespace/view/table that he is trying to access. As per the IBM documentation -551 SQLCODE states that.Example-551 auth-id DOES NOT HAVE THE PRIVILEGE TO PERFORM OPERATION ... Read More

Both QMF and SPUFI are tools built to access DB2 databases in a mainframe environment. Using these tools, we can SELECT, UPDATE and DELETE the data from the DB2 database. QMF stands for Query Management Facility and SPUFI stands for SQL Processor Using File Input.Below are the differences between QMF ... Read More

The OPTIMIZE FOR N ROWS is a DB2 clause which we can add in the query to give priority for the retrieval of the first few rows only. This clause will enable the optimizer to choose the access path that minimizes the response time for fetching first few rows.The OPTIMIZE ... Read More

The TRIGGERS are the event driven database programs which are triggered automatically by the database. The TRIGGERS are created using the CREATE TRIGGER statement.For example, we want to create a TRIGGER which will update ORDER_COMMISION column of the ORDERS table to 5% of the ORDER_TOTAL value after every new record ... Read More

The TRIGGERS are database programs which are triggered automatically by DBMS in response to any modification done on the specified table. A TRIGGER can be associated with only a single table and they cannot be skipped if the desired event occurs.The TRIGGERS are like STORED PROCEDURES in the sense, both ... Read More