Answer and provide 1 reference. Advanced SQL and PL/SQL Respond to this discussion Response: Sub queries are important and advantageous because they are structured in such a way that they isolate each part of the statement, and perform the same operation that would ordinarily require complex and joins and unions and they ae easier to read. Base on how the database optimizer processes them can cause them the take longer to execute. The Structured Query Language (SQL) provide the basis for sub queries due to its easily readable structure. They provide a powerful means to combine data from two tables into a single result. Sub queries are also known as nested query or inner query such as defined by Covrett stating that “A subquery is a “SELECT” statement within the “WHERE” or “HAVING” clause of an outer “INSERT,” “UPDATE,” “MERGE” or “DELETE” statement. The subquery also is called the “inner query” or “inner select.” The subquery may have a “FROM” clause with one or more tables and may optionally have a “WHERE,” “GROUP BY” or “HAVING” clause. It is always enclosed in parenthesis.” PL/SQL is an extension of Structured Query Language (SQL) that is used in oracle. It allows the programmer to write code in a procedural format. It’s purpose is to combine database language and procedural programming language. Advantages of PL/SQL: Tight Integration with SQL. gh Performance. gh Productivity. Portability. Scalability. Manageability. Support for Object-Oriented Programming. Support for Developing Web Applications. Covrett, L. What Are the Advantages & Disadvantages of a Join or a Subquery? https://www.techwalla.com/articles/what-are-the-advantages-disadvantages-of-a-join-or-a-subquery Purchase the answer to view it
