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Editor's Notes

• #5: A simple list created in Microsoft Excel (as a spreadsheet) or in Microsoft Word (as a table) is often sufficient to organize simple tasks.When complex information needs to be organized or more than one person needs to access it, a list no longer is efficient. Data duplicatedbetween two lists causes data redundancy.Each time information in the list changes, multiple lists might need to be updated. It would be easy to overlook one or more lists or even one or more rows in the same list. This would lead to a state of data inconsistency.If data is entered twice, any reports that are generated based on this list will be inaccurate because of the duplicate data.Reorganizing (or sorting) multiple lists can be labor intensive.A final problem with lists is how to handle incomplete data.
• #21: To extract records from a database, you use a query language. Almost all relational and object relational databases today use structured query language, or SQL. E. F. Codd, who has been called the father of relational databases, proposed a standardized query language when working at IBM in the mid-1970s. The original language was called SEQUEL, short for structured English query language. The idea was to make queries easy by using English language–like sentence structure. Oracle first introduced SQL in a commercial database product in 1979. It has been the de facto standard language for relational databases since then.SQL uses relational algebra to extract data from databases. Relational algebra is the use of English-like expressions that have variables and operations, much like algebraic equations.
• #24: Relationships in databases can take three forms: one-to-one, one-to-many, or many-to-many. A one-to-one relationship indicates that for each record in a table, there is only one corresponding record in a related table. For example, a parking space can be occupied by only one car at a time, so a table that links assigned parking spaces to a table of faculty members would have a one-to-one relationship. One-to-one relationships occur most frequently in relational databases.A one-to-many relationshipis characterized by a record in one table being related to multiple records in another table. For example, students can register for many classes, but each registration record can be related to only one student.Many-to-many relationships are characterized by records in one table being related to multiple records in a second table and vice versa. For instance, a table of students could be related to a table of student employers. The employers could employ many students, and students could work for more than one employer.��
• #39: Enterprise resource planning (ERP) systemsare broad-based software systems that integrate multiple data sources and tie together the various processes of an enterprise to enable information to flow more smoothly. ERP systems use a common database to store and integrate information to enable the information to be used across multiple areas of an enterprise.
• #42: As databases have become commonplace, there is an ever-increasing amount of information about you and your habits located in various databases. Every time you purchase something with a credit card, there is a record of that transaction, and both the merchant from whom you purchased the item and the credit card company have information about your buying habits.All banking transactions are handled by computers (and hence databases) in the United States, and there is a high probability that your employer is electronically transferring your pay to your bank by direct deposit. And if you engage in online banking and bill paying, then there is another electronic trail of your financial life being generated in databases.Think you can avoid scrutiny by paying cash? Not if you are a member of a frequent buyer club (popular with supermarkets and drug stores for granting discounts) and provide the checkout clerk with your personal information in exchange for coupons or a few dollars off your purchases. And you never can be sure what this data might be used for.The majority of physicians, hospitals, and pharmacies in the United States track medical records in electronic databases. Discrete pieces of data such as filling your gas tank last Thursday or buying a copy of War and Peace last month don’t mean much in and of themselves. But with so much data in electronic form, it is getting much easier to combine data from various data sources and build powerful profiles of an individual to which data mining techniques can be applied.
• #43: For what purpose is the data being gathered?��When the clerk at the electronics superstore asks for your zip code, ask why she wants it (it is probably for some marketing purpose).Are the reasons for gathering the data legitimate or important to you?��For warranty purposes on a large-screen TV, you might need to give a clerk your address and zip code. For purchasing a CD, is asking for your zip code really a legitimate request? However, disclosing medical information to key people (such as your pharmacist) may be important to receiving good care and therefore is extremely important to you. If you don’t see the advantage, then ask more questions or don’t reveal the information.How will the information gathered be protected once it has been obtained?��Ask about data protection policies before you give information. Most Web sites provide access to their data protection policies—readily available through clickable links or pop-up boxes—when they ask for information. If an organization doesn’t have a data protection policy, then be wary of providing them sensitive information unless there is a compelling advantage to doing so (such as receiving good medical care). And data protection doesn’t just refer to keeping data secure. It also means restricting access to the data to employees of the organization that need to use that data. A shipping clerk might need to see your address, for example, but doesn’t need to see your credit card information.Will the information collected be used for purposes other than the purpose for which it was originally collected?��This might be covered in a data protection policy. If it isn’t, then ask about it. Will your information be sold to other companies? Will it be used for marketing other products to you?Could the information asked for be used for identity theft?��Identity thieves usually need Social Security numbers and your birth date to open credit card accounts in your name. Be especially wary when asked for this information and make sure there is a legitimate need for this information. Most organizations and businesses are shying away from using Social Security numbers to track customers because of the risk of identity theft.Are organizations that already have your data safeguarding it?��Don’t just consider new requests for information. Think about organizations that already have your information and monitor their performance. Have they been in the news lately because of a major data breach (inadvertently exposing information to inappropriate or unauthorized individuals)? You might want to consider switching institutions (such as a bank) if they have poor track records of data security.