quescol In a Database Management System (DBMS), an aggregate function is a special tool that performs calculations on a set of values to return a single value. It simplifies data analysis by summarizing large volumes of data. How Aggregate function works? Common Aggregate Functions 1. SUM Adds together all the numerical values in a specified column. … Read more
SQL is a popular programming language, which is used to manage the relational databases and to perform various operations on its data. In a relational database, data is stored in tabular form, and there are proper defined rows and columns in each table where data is stored. The full form of SQL is the Structured … Read more
In SQL, virtual table are considered as views. Like Tables, views also contain rows and columns. We can select the fields from one or more tables to create the view. It can either have all the rows of a table or have some specific rows based on certain condition. Detailed Answer What is View? In … Read more
1. SYSDATE Purpose: SYSDATE is a function that returns the current date and time of the database server. Syntax Example Use: It’s often used to get the current date and time for record keeping, such as logging when a transaction occurred. 2. TO_DATE() Purpose: TO_DATE() is a function used to convert a string into a … Read more
1. Super Key A super key is an attribute or a set of attributes within a table that uniquely identifies each row in that table. A super key can consist of a single column or multiple columns combined. The defining characteristic of a super key is its ability to ensure that no two rows have … Read more
A Cursor is essentially a temporary work area created in the system memory that comes into play during the execution of DML statements like INSERT, UPDATE, and DELETE. It enables the processing of multiple rows of data, one row at a time, ensuring careful manipulation of database records. Cursors are invaluable tools in the context … Read more
Relational algebra is a formal language used to query and manipulate data stored in relational database systems. It provides a set of operations that take one or two relations (tables) as input and produce a new relation as output, effectively enabling the construction of complex queries from simpler ones. Relational algebra operations are foundational to … Read more
The relational model is a type of model, which represents how the data are stored in a relational database. In a relational database, data is stored in the form of tables (relations). Tables are a combination of rows and columns. In a table, columns represent an attribute of an entity, and rows represent records. The … Read more
User-Level Threads Advantages of User-Level Threads Disadvantages of User-Level Threads Kernel-Level Threads Advantages of Kernel-Level Threads Disadvantages of Kernel-Level Threads
User-level and kernel-level threads represent two approaches to thread management in operating systems. Both have some differences Difference Between User-level and kernel-level thread 1. Management and Overhead 2. Performance and Efficiency 3. Resource Sharing and Synchronization 4. Scalability and Flexibility 5. Control and Customization 6. Example Use Cases User-level VS Kernel-level Threads Feature User-Level Threads … Read more