The SQL Procedure: Trivia Quiz

Explanation
A self-join is a type of query where a table is joined with itself. This is done by creating two instances of the same table and then joining them based on a common column. It is often used when there is a need to compare records within the same table. In a self-join, each instance of the table is treated as a separate entity, allowing for comparisons and analysis between the two.

Explanation
Single-row functions are built-in functions that operate on a single row of data at a time and return a single result for each row. These functions can be used to manipulate data values within a query, perform calculations, or apply transformations to the data. Examples of single-row functions include mathematical functions (such as ABS or ROUND), string functions (such as SUBSTR or CONCAT), and date functions (such as TO_CHAR or MONTH). By applying single-row functions to the retrieved data, we can modify or format the values as needed before displaying or using them further.

Explanation
The SYSDATE pseudocolumn is a single-row function that returns the current date and time. It can be used in SQL queries to retrieve the current date and time and perform calculations or comparisons based on it.

Explanation
A table alias is an alternative name that you assign to a table in a query's FROM clause. This allows you to refer to the table using a shorter or more meaningful name within the query. Table aliases are especially useful when you need to join multiple tables in a query, as they help to clarify which table each column belongs to. By using table aliases, you can make your query more concise and easier to read and understand.

Explanation
The correct answer is "Transaction" because a transaction is a series of action queries that represent a logical unit of work. In a transaction, multiple queries are executed together as a single unit, ensuring that either all the queries are successfully executed or none of them are executed. This helps maintain data integrity and consistency in the database.

Explanation
Truncate is the correct answer because it removes all of a table's data without saving any rollback information. Unlike the delete statement, which can be rolled back, truncate cannot be undone. It is a faster and more efficient way to remove all data from a table when rollback is not necessary.