What is a Database SQL?

What is A Database?

Databases are also considered containers. They hold the objects that make up your server’s purpose in life. Tables, views, indexes, and stored procedures are all objects that reside in your database. You can, and often will, have multiple user-defined databases residing on your server. These databases are where the production information and code reside. Other databases are installed on your server to give it the intelligence it needs to function; I will cover these databases in a few different areas throughout the book. However, our focus will be on setting up a production system, not on the inner workings of Microsoft SQL Server.

One of the most common mistakes new users make is to confuse the device and the database. You place your databases within your devices. To understand this, think of a database as a division within your company. For instance, Human Resources deal with very specific kinds of information, so you would logically put all of that type of information in a container for centralized management and access control. Accounting is an area that often requires more security than others, and the information generated from this area would justly be placed in a separate container for security reasons. You would not scatter information for the Human Resources department throughout all the offices; instead, you would put all those functions and resources in one place. The same applies to databases and good database design.

An interesting point for all PC-based database programmers is that Microsoft SQL Server does not store the information or data in the database. Remember, the database is a container. Instead, the server stores your data in a table. The index you create for fast access to data is not stored in the table with the raw data; it is stored as another object within the database. A database is a collection of objects. This concept is not hard to follow, but it is different enough from the organization of other database programs that it is sometimes a stumbling block for the small-system programmer. An MIS department accustomed to dBASE or Microsoft FoxPro databases will struggle with this at first. Since this structure is common to most large database systems today, you should become familiar with it.

In addition, you should focus on the database level when administrating your system’s security. Your users will be granted a logon ID for connecting to the server, but this does not allow them to get to the data they need. This is done by adding users and groups to each database individually on a need-to-know basis. This method of security keeps unwanted users from browsing where they should not while allowing others to do their jobs.

Returning to the office analogy, let’s compare a database to the Accounting department in your company. This department might have a door you must pass through, and once you pass through that door, you would see all the cubicles and desks where the actual work is done. This door might be locked in the evening or even require a passkey to enter during the day.

The same idea can be applied to a database. The records and files are not strewn around the office; they reside in filing cabinets and in folders or ledgers for ease of access. These organizational tools can be related to Microsoft SQL Server objects. You use tables, stored procedures, and indexes to find what you need when you need it.

The security model that Microsoft SQL Server uses is also similar to the passkey entry requirement. No one gets access without a valid key or password. I will not try to recommend a security method here because of the diverse requirements in the market today. However, I will say that Microsoft SQL Server will accommodate a strict security model very well and still allow for the simple, trusting models required by smaller companies growing into Microsoft SQL Server.

During installation of Microsoft SQL Server, you will not be concerned with these divisions or security, but you should make a few assumptions on the amount of disk space you will need to accommodate these areas and how you will accommodate these needs.