Technical Interview Questions
Components of physical database structure are given below. One or more data files. Two or more redo log files. One or more control files. The physical database structure of an Oracle database consists of the following components: Datafiles: These are the actual physical files on disk where the data is stored. An Oracle database is … Read more
There are two types of cursors in PL/SQL. Implicit cursor, and explicit cursor In PL/SQL, there are two main types of cursors: Implicit Cursors: These cursors are created by default when DML (Data Manipulation Language) statements like SELECT, INSERT, UPDATE, or DELETE are executed. They are automatically created and managed by the Oracle database engine. … Read more
A cursor is a temporary work area created in a system memory when an SQL statement is executed. A cursor contains information on a select statement and the row of data accessed by it. This temporary work area stores the data retrieved from the database and manipulate this data. A cursor can hold more than … Read more
Consistency simply means that each user sees the consistent view of the data. Consider an example: there are two users A and B. A transfers money to B’s account. Here the changes are updated in A’s account (debit) but until it will be updated to B’s account (credit), till then other users can’t see the … Read more
Mutating table error is occurred when a trigger tries to update a row that it is currently using. It is fixed by using views or temporary tables. In PL/SQL, a mutating table error occurs when a trigger or stored procedure references a table that is currently being modified by the statement that invoked the trigger … Read more