A data warehouse is a large collection of data that can be used to help an organisation make key business decisions.
Here’s a more precise definition of the term, as coined by Bill Inmon, (considered by many to be “the father of data warehousing”):
A data warehouse is a subject-oriented, integrated, nonvolatile, and time-variant collection of data in support of management’s decisions.
The term big data refers to the massive amounts of data – both structured and unstructured – that inundate organisations on a day-to-day basis.
Typically, big data is so large, and accumulates so fast, that traditional data storage and processing applications are inadequate.
The big data industry helps organisations capture and analyse their big data, so that those organisations can make more informed business decisions.
DBMS stands for Database Management System.
A database management system is an application that enables the creation and administration of databases. Database management system is a broad term that includes any system that performs that function.
The most common type of DBMS is an RDBMS (Relational Database Management System). RDBMSs allow you to create relational databases – databases that have multiple tables that contain related data.
The Input Mask Wizard is a feature of Microsoft Access that helps you create an input mask.
An input mask allows you to specify exactly how data should be entered into the database. It’s an expression that specifies certain rules about how the data should be formatted as it is entered into the system.
Here’s an example of an input mask:
(999) 000-0000
This specifies the format that a phone number must be entered. The number 9 indicates an optional character. The number 0 specifies a mandatory one. So in this example, the area code is optional.
The Expression Builder is a component of Microsoft Access that helps you build expressions. It allows you to look up and build expressions without having to remember how to type the full expression.
In database terms, a schema (pronounced “skee-muh” or “skee-mah”) is the organisation and structure of a database. Both schemas and schemata can be used as plural forms.
A schema contains schema objects, which could be tables, columns, data types, views, stored procedures, relationships, primary keys, foreign keys, etc.
A database schema can be represented in a visual diagram, which shows the database objects and their relationship with each other.
Above is a simple example of a schema diagram. It shows three tables, along with their data types, relationships between the tables, as well as their primary keys and foreign keys.
MySQL is an open source relational database management system (RDBMS). It is the world’s most popular open source RDBMS and is currently ranked as the second most popular RDBMS in the world (behind Oracle Database).
MySQL is available as a free download, however, several paid editions are also available which offer additional functionality.
As the name suggests, MySQL is based on SQL. The “My” part is named after co-founder Michael Widenius’ daughter, My.
Microsoft Access is a relational database management system (RDBMS) developed by Microsoft. It’s part of the Microsoft Office suite, included in the Professional and higher editions or sold separately.
Microsoft Access provides a quick and easy way to develop databases and is particularly well suited for individuals and small business. Access is the most popular desktop database on the market.
In Access, most tasks can be performed via the graphical user interface (GUI), but more advanced users can also develop applications using Visual Basic for Applications (VBA) code. Advanced users can also use SQL code to write or modify queries.
SQL Server is a relational database management system (RDBMS) developed by Microsoft. It is Microsoft’s enterprise level RDBMS offering, and is a more sophisticated and robust system than Access, which has traditionally been a desktop system.
SQL Server’s main competitors are Oracle Database, MySQL (now owned by Oracle), PostgreSQL, and IBM’s DB2.
SQL Server is a client-server based system, which means that it operates as a server, typically containing many databases, with multiple clients accessing the databases from across a network. These clients are often other applications (such as a website or CRM system). This is in contrast to desktop systems, where the database will often (but not necessarily) reside on the user’s computer.
SQL is the standard language for querying data inside a relational database management system (RDBMS). It is supported by all of the major database systems, such as Microsoft Access, SQL Server, MySQL, Oracle, PostgreSQL, DB2, etc.
SQL is a relatively easy language to learn when compared to most programming languages. It is based on SQL “statements” that, at times, can resemble natural language.
For example:
SELECT CustomerName FROM Customers WHERE CustomerId = 1
The above SQL statement is asking the database to:
“Select the value of the CustomerName column from the Customers table where the CustomerId column’s value equals 1“.