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Most of the discussion below assumes that there is an existing database management system (DBMS) and that QlikView is used as an output tool. The arguments, however, still hold true when the raw data are in the form of text files.
Data Security and Integrity
Data protection usually means several different things. It can mean protecting entered data from being altered or destroyed by mistake, making sure that data is entered in a correct way or preventing the data from being shared by unauthorized people.
The terms integrity and security are often used in this context and although the two concepts seem similar at a first glance, they are in fact quite different. Security refers to the protection of data against unauthorized access, whereas integrity refers to the validity of data, i.e.:
- Security involves assuring that the users are allowed to do what they are trying to do.
- Integrity involves assuring that what the users are trying to do is correct.
We will mostly discuss data security, since the tools for data integrity are provided by the DBMS.
The Right to Alter Data
The first step in security is to make sure that users cannot erase or change data inadvertently. For multi-user systems this implies using an operating system and a database management system with adequate protection. Examples of such operating systems for PCs are Windows NT or Novell. Examples of such database management systems are ORACLE, SQL Server or Informix.
If data are not protected by the operating system, it will always be possible to delete data by mistake. This is true even if the file is password protected.
The next step is to set up privileges for the authorized users. In a correctly set up system it should be impossible to do anything with the data unless the correct tools are used, i.e. tools that can check whether you are authorized to do what you are trying to do.
For the single user most of the security problems do not exist. It is thus often sufficient to make regular back-ups of the data files.
The Right to View Data
The final issue in data security concerns the security when handling confidential information. If the security issues above concern the right to alter data, this point rather concerns the right to view data. Most database management systems have means to prevent people from looking at data residing in the database. They cannot, however, prevent people from looking at a copy of the data found in a QlikView file. For this purpose, QlikView has its own means of preventing unauthorized people from viewing data. One must, however, be aware of the fact that the QlikView access restriction tool only concerns the right to see data. QlikView can never prevent users from destroying data with other tools. Only the operating system can.
Data integrity implies a structured data flow. Data entry procedures must be set up to make sure that data are entered in a uniform way. A good way to do this is to design forms with the DBMS. Forms also prevent users from entering non valid values, e.g. nonexistent customer numbers, into a database.
When working with single-user databases, one must also be careful not to have more than one person using the database at a time. Multi-user databases can, as the name implies, handle several people editing the database simultaneously.
Another aspect related to this issue is the following: One must always know if a file or a database is the original or a copy. If this is not the case, someone will most certainly start entering data into a copy of the database.