Relational Databases

What are relational databases? What are their advantages? Well, ease of use, flexibility, security, and performance are some of them. For an overview of relational databases and their advantages, read this Techspirited article.

What is a Database?
A structured collection of records is known as a database. The way in which a database is structured is defined by the database model. Hierarchical model, network model, object model, and relational model are some of the most commonly used models in the structure of databases. A database facilitates an organized storage of data in the form of records. The records can be queried in different ways to retrieve information from the database. Owing to organized storage of data, a database becomes a useful tool of data storage. Databases form the basic tier of any multi-tier system. The information handled and manipulated by the other layers of an n-tier system is basically stored in a structured manner in a database. Take an example of any organization. How do you think they store their employee and customer information? Yes, they store it in a database. Imagine a website and where do you think the site maintains the log-in information about its users? Again, the answer is – a database.

After having realized the utility of databases in software systems, let us introduce ourselves to this concept. A database is composed of tables, which are composed of records. There is a primary key associated with every record and it serves as its unique identification. Every record has a unique primary key and also the information about the entity associated with that record. Each field in the database can be called attribute and data from a table can be retrieved on the basis of database attributes. Search queries enable easy data retrieval from the table, thus proving the importance of the organized nature of data in a database.

An Introduction to Relational Databases
One of the most popularly used database models is the relational model. It was developed by Edgar Codd in 1969. This model provides a declarative method for specification of data and queries. In a relational model of a database, the database users directly state the information they want to be retrieved from it and abstract away from the responsibility of describing the data structures that are used to store data. A database that confirms to the relational database model is known as a relational database.

A relational database is a collection of relations or tables. The rows of a table in a relational database are known as tuples and each column of a table is called an attribute. By definition, a relation becomes a set of tuples having the same attributes. Operations, which can be performed on the relations are select, project, and join. The join operation combines relations, the select queries are used for data retrieval and the project operation identifies attributes. Similar to other database models, even relational databases support the insert, delete, and update operations. Let us now look at the advantages of relational databases.


Support to Operations Based on Set Theory: Basically, relational databases are based on relational set theory. Normalization is a vital component of the relational model of databases. Relational operations, supported by relational databases work best with normalized tables. A relational database supports relational algebra, consequently supporting the relational operations of set theory. Apart from mathematical set operations namely, union, intersection, difference, and Cartesian product, relational databases also support select, project, relational join, and division operations. These operations are unique to relational databases.

Dynamic Views: Relational databases support an important concept of dynamic views. In this database, a view is not a part of the physical schema, it is dynamic. Hence changing the data in a table alters the data depicted by the view. Views can subset data, join and simplify multiple relations, dynamically hide the complexity in the data, and reduce data storage requirements.

Simple Operations and Defined Relationships: Relational databases use SQL, which is an easy and human-readable language. SQL instructions are in the form of plain instructions, which can be put to the database for implementation. Most of the database vendors support the SQL standard. A competitive technology of flat files supports a sequential storage of data and fails to provide the users with search and query options. On the other hand, relational databases provide the users with simple operations to manipulate data in the databases and retrieve it. Moreover relational databases establish defined relationships between tables, thus giving their users a complete picture of the data stored.

Security: Relational databases provide excellent security. They support access permissions which allow the database administrator to implement need-based permissions to the access of data in database tables. Relational databases support the concept of users and user rights, thus meeting the security needs of databases. Relations are associated with privileges like create privilege, grant privilege, select, insert, and delete privileges, which authorize different users for corresponding operations on the database.

The other important advantages of relational databases include their performance, power, and support to new hardware technologies, as also flexibility and a capacity to meet all types of data needs. These databases are scalable and provide support for the implementation of distributed systems.

Owing to their advantages and application in the operations of data storage and retrieval, relational databases have revolutionized database management systems.

Parallel computing

Parallel computing is a type of computation in which many calculations or the execution of processes are carried out simultaneously.Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-levelinstruction-leveldata, and task parallelism. Parallelism has long been employed in high-performance computing, but it’s gaining broader interest due to the physical constraints preventing frequency scaling.As power consumption (and consequently heat generation) by computers has become a concern in recent years,parallel computing has become the dominant paradigm in computer architecture, mainly in the form of multi-core processors.

Parallel computing is closely related to concurrent computing—they are frequently used together, and often conflated, though the two are distinct: it is possible to have parallelism without concurrency (such as bit-level parallelism), and concurrency without parallelism (such as multitasking by time-sharing on a single-core CPU).]In parallel computing, a computational task is typically broken down into several, often many, very similar sub tasks that can be processed independently and whose results are combined afterwards, upon completion. In contrast, in concurrent computing, the various processes often do not address related tasks; when they do, as is typical in distributed computing, the separate tasks may have a varied nature and often require some inter-process communication during execution.

Parallel computers can be roughly classified according to the level at which the hardware supports parallelism, with multi-core and multi-processor computers having multiple processing elements within a single machine, while clustersMPPs, and grids use multiple computers to work on the same task. Specialized parallel computer architectures are sometimes used alongside traditional processors, for accelerating specific tasks.

In some cases parallelism is transparent to the programmer, such as in bit-level or instruction-level parallelism, but explicitly parallel algorithms, particularly those that use concurrency, are more difficult to write than sequential ones,because concurrency introduces several new classes of potential software bugs, of which race conditions are the most common. Communication and synchronization between the different sub tasks are typically some of the greatest obstacles to getting good parallel program performance.

Importance of Employee Cyber-security Training

Recent reports from Trust-wave reveal that despite companies spending $96 billion on cyber security initiatives this year, 100 percent of all web applications continue to be vulnerable to attacks. To protect your company’s data from threats, it’s increasingly critical that employee cyber security training takes place in the workplace.

Tips for Employee Cyber-security Training

Cyber security for your company starts with your employees. Utilize the following tips to secure your data and conduct employee cyber security training.

1. Include All Staff Members

No one is immune to hackers and cybersecurity attacks, so ensure all team members complete training. Don’t forget to include upper management, as well as IT department staff.

2. Review Signs of an Attack

One of the most important lessons in cybersecurity is recognizing signs of an attack. Review common signs that a device or network is under attack such as:

  • Systems running slowly
  • Abnormal activity on the corporate firewall
  • Access logs showing unusual login times and locations
  • Frequent pop-ups
  • Device freezing or crashing

These are just a few ways that attacks may be happening in your office. Encourage employees to alert you if they notice any of the above, or other unusual autonomous activity.

NOTE: Ensure employees that there’s no such thing as a silly question. It’s better to report a problem and it be a false alarm, than to go without reporting a problem and compromise your entire company network.

3. Explain Password Policies

One simple way that employees can safeguard their information, as well as company data, is using secure passwords. An employee’s password should contain a combination of various letters, symbols, numbers and capitalizations. No two programs or websites should have the same login credentials.

As you can imagine, remembering all of these long, unique passwords can be difficult. Consider investing in password management software like Last Pass for your business to help employees keep track of their secure passwords.

4. Go Over Preventative Measures

In addition to explaining the importance of password management, your employee cybersecurity training should include information on measures to prevent attacks and security breaches altogether. Provide your employees with the following tips to prevent attacks:

  • When accessing company data remotely, implement multifactor authentication.
  • Keep your operating systems, browsers, and antivirus and security software up-to-date.
  • Regularly update your passwords.
  • Never open attachments or click on links from an unknown sender.
  • Never share sensitive information via email.
  • Back up critical business files and data using cloud services

For more tips on preventing cyber attacks, utilize the Department of Homeland Security’s Stop.Think.Connect. for small and mid-size business resources. Stop.Think.Connect. is a public awareness campaign with the goal of educating users on cyber threats.

By helping employees understand the threat landscape and how to prevent network vulnerabilities, you are able to make cyber security a part of your company culture. For more information on how to protect your business from cyber attacks and to conduct employee cyber security training, contact your nearest Computer Troubleshooters office.

About Phishing

About Phishing

Most types of threats to computer users usually involve direct attacks on a computer, targeting physical vulnerabilities of a computer’s operating system and other software. Phishing, on the other hand, relies solely on the computer user’s own vulnerabilities, namely the same emotions and ignorance that allows people to be taken in by non-electronic confidence schemes.

In the digital world, phishing is any attempt to defraud a computer user by pretending to be a reputable source. This can be done through e-mails, on a fake Web site, or a combination of the two. The end result of phishing can range from a person giving away their login and password information, or giving out their credit card information, or in the most severe cases, kidnapping or murder.

Unlike malware such as virusesworms, and rootkits, which may look to either damage computers or open a back door for identity thieves, phishing attempts always seek to commit identity theft and nothing else.

The term “phishing,” by most accounts, is a combination of “fishing” (as in baiting a hook with a fraudulent e-mail) and “phreaking,” a form of phone-based fraud.


Social Engineering

Phishing is a form of social engineering. Social engineering is the act of manipulating a person into giving out sensitive information, rather than by outright stealing the information.

One way to look at the difference is to compare phishing to another computer attack: keylogging. With keylogging, a cybercriminal physically breaks into a computer to implant a program that can record the text that the unsuspecting user types, especially information such as passwords and credit card numbers. On the other hand, a phishing e-mail may try to trick the computer user into thinking that their bank needs to verify their account login and password.


Examples of Phishing

Some of the earliest wide-spread phishing attacks occurred via AOL. Phishers would pretend to be AOL staff, and using the in-house instant messaging system, ask AOL members to verify their login and password. This would allow the phisher to log in under this account, having access to other account information (such as a credit card number), or to set up a base to send spam e-mails. Even after AOL inserted text warning that AOL staff would never ask for account information, some people still fell for the phishing. What made matters worse was when AOL opened up their instant messaging program to non-AOL account users. This allowed phishers to attempt the same scam to AOL subscribers while being outside of the bounds of the company’s Terms Of Service agreement.

The success of the AOL phishing led to the prolific use of phishing geared toward customers of reputable banks, online businesses, and payment services. Companies such as TD Ameritrade, eBay, and the U.S. Internal Revenue Service have all been targets for phishers. Usually perpetrated by e-mails, phishers will design e-mails that look remarkably like they came from the actual business, except for a few details, such as a letter addressed to “Dear Client” instead of a person’s name, or the sender’s e-mail address does not come from the business’ domain.

Phishers also use Web site forgeries to commit crimes. Through this method, phishers redirect a Web site’s patrons onto a reasonable copy of a reputable site in order to record their personal information.


419 Scams

Many people associate 419 Scams (also known as Nigerian bank scams) with phishing. However, most of these types of e-mail scams do not involve an attempt to fool the target into thinking the sender is from a business the recipient uses. Most of these types of scams generally just involve social engineering, preying on people’s greed and empathy, usually culminating a wire transfer of money with the expectation of being rewarded by more money in the future (which, of course, never comes). Most of these are created with Web-based e-mail programs and are generally poorly worded and full of factual and grammatical errors.


Preventing Phishing

By its very nature, there are few things that a person can do to their computer to prevent being a victim of phishing. As mentioned before, phishing targets a person’s vulnerabilities rather than a computer’s.

Buying subscription-based antivirus software that specifically targets phishing is one way to help prevent being scammed. Keeping antivirus software up to date can help keep a computer protected against ever-evolving threats. The antivirus software can block offending e-mails that come from a suspect source or contain phrases common to many phishing attempts. Antivirus software like  Norton SecurityKaspersky Security, Mcafee Security, AVG Security can also warn subscribers when they’ve stumbled upon a unreliable Web site.

However, even with antivirus software in place, computer users can still ignore the warning signs. They can disable certain functions of antivirus software. And, some phishers have begun sending e-mail text in an image in order to circumvent antivirus trackers.

When it comes down to it, the most important way to prevent phishing is to be informed. No reputable company will ever ask their customers for account numbers, credit card numbers, logins, or passwords. Never enter sensitive information on a Web site that isn’t on a secure connection. And if any e-mail or Web request just doesn’t feel right, disregard it. And make sure all users of a computer are familiar with phishing and how to recognize it.

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