This document discusses database systems and SQL. It describes the database server model where a database server stores data and authenticates and processes client requests to retrieve and display requested data. It also discusses the AMP stack which is a combination of Apache, MySQL, and PHP that is commonly used due to its low cost and open source applications. The document further discusses Oracle and Microsoft SQL Server as popular closed-source database technologies and NoSQL as emerging non-relational database technologies like Cassandra used by Facebook.

1. Database Systems and
SQL

2. Database Sever Model
 Stores data which can be accessed via a database server when requested by
the client.
 Database server software:
 Authenticates client requests to access the database.
 Executes the query used to retrieve data from the database – might be required in
a certain format.
 Displayed the requested data using the database manager or the server-side script
if further processing is required.

3. Database Server Model

4. *AMP Stack
 *AMP is a term used to design a combination of operating system, Apache Web
Server, MySQL database server and PHP.
 *AMP is popular due to the low cost of development and open source
applications – free software, no licences.
 Examples:
 apple.com, paypal.com, adobe.com, twitter.com
 MySQL is the key database component of *AMP and controls online databases
services.
 This database technology drives popular web tools such as Tumblr and Twitter.

5. Oracle, SQL, Server, NoSQL
 Oracle Database and Microsoft SQL Server are
 There are many other database server technologies that are used. Oracle
Database and Microsoft SQL Server are two popular closed-source, large scale
database technologies which are extremely robust and well supported by both
companies.
 NoSQL is term used to describe a range of emerging database technologies which
don't follow a traditional relational database approach. NoSQL databases evolved
from the need to query sometimes millions of records in a fraction of a second,
often with elements of the database running on separate servers. Facebook
developed a NoSQL database management system called Cassandra, to cope with
the need to process large amounts of data, across multiple servers, in multiple
locations. Cassandra is now an open source project under the care of the Apache
Foundation.

6. What you need to know…
 You should now know how to create and execute SQL statements:
 To create database tables (including the use of fields, keys and field types);
 To insert, update and delete data from tables;
 Making use of FROM, WHERE, ORDER BY and GROUP BY clauses.
 Functions (COUNT, SUM, MIN, MAX, AVG) and equi-joins between tables.
 You should also be able to describe the database server model.