Codd's rule of RDBMS

Also called Codd's Law, a set of 13 rules used to determine if a DBMS can be considered a relational DBMS (RDBMS). In 1985, Dr. E. F. Codd first published this list of rules that became a standard way of evaluating a relational system. The rules have since been expanded by others, and after publishing the original article Codd stated that there are no systems that will satisfy every rule. Following are Codd's original 13 rules:

• Often referred to as rule 0, this rule states that all subsequent rules are based on the notion that in order for a database to be considered relational, it must use its relational facilities exclusively to manage the database.
• 1. The Information rule: All information in an RDBMS is represented logically in just one way - by values in tables.
• 2. The Guaranteed Access rule: Each item of data in an RDBMS is guaranteed to be logically accessible by resorting to a combination of table name, primary key value, and column name.
• 3. The Systematic Treatment of Null Values rule: Null values (distinct from an empty character string or a string of blank characters and distinct from zero or any other number) are supported in a fully relational DBMS for representing missing information and inapplicable information in a systematic way, independent of the data type.
• 4. The Dynamic Online Catalog Based on the Relational Model rule: The database description is represented at the logical level in the same way as ordinary data, so that authorized users can apply the same relational language to its interrogation as they apply to the regular data.
• 5. The Comprehensive Data Sublanguage rule: A relational system may support several languages and various modes of terminal use (for example, the fill-in-blanks mode). However, there must be at least one language whose statements are expressible, per some well-defined syntax, as character strings and whose ability to support all of the following is comprehensible: data definition, view definition, data manipulation (interactive and by program), integrity constraints, and transaction boundaries (begin, commit, and rollback).
• 6. The View Updating rule: All views of the data which are theoretically updatable must be updatable in practice by the DBMS.
• 7. The High-level Insert, Update, and Delete rule: The capability of handling a base relation or a derived relation as a single operand applies not only to the retrieval of data but also to the insertion, update, and deletion of data.
• 8. The Physical Data Independence rule: Application programs and terminal activities remain logically unimpaired whenever any changes are made in either storage representations or access methods.
• 9. The Logical Data Independence rule: Application programs and terminal activities remain logically unimpaired when information preserving changes of any kind that theoretically permit unimpairment are made to the base tables.
• 10. The Integrity Independence rule: Integrity constraints must be definable in the RDBMS sub-language and stored in the system catalogue and not within individual application programs.
• 11. The Distribution Independence rule: An RDBMS has distribution independence. Distribution independence implies that users should not have to be aware of whether a database is distributed.
• 12. The Nonsubversion rule: If the database has any means of handling a single record at a time, that low-level language must not be able to subvert or avoid the integrity rules which are expressed in a higher-level language that handles multiple records at a time.

Digital laws

Moore's Law -- The observation made in 1965 by Gordon Moore, co-founder of Intel, that the number of transistors per square inch on integrated circuits had doubled every year since the integrated circuit was invented. Moore predicted that this trend would continue for the foreseeable future. In subsequent years, the pace slowed down a bit, but data density has doubled approximately every 18 months, and this is the current definition of Moore's Law, which Moore himself has blessed. Most experts, including Moore himself, expect Moore's Law to hold for at least another two decades.

Kryder's law is the storage equivalent of Moore's Law ,Seagate's vice president of research said back in 2005 that magnetic disk storage density doubles approximately every 18 months.That also means the cost of storage halves every eighteen months, enabling online services to give us more storage without charging any more for it.

Wriths law - Niklaus Wirth has, and in 1995 observed that "software is getting slower more rapidly than hardware becomes faster." Wirth's law has been invoked by, and wrongly credited to, both Google's Larry Page and Microsoft's Bill Gates.

Rule 34—"If it exists, there is porn of it. No exceptions"—is a prevalent meme that Internet pornography exists for every conceivable topic. Rule 34 is one of the best-known Internet adages in current usage.

Fitts's law (often cited as Fitts' law) is a model of human movement primarily used in human–computer interaction and ergonomics that predicts that the time required to rapidly move to a target area is a function of the distance to the target and the size of the target. Fitts's law is used to model the act of pointing, either by physically touching an object with a hand or finger, or virtually, by pointing to an object on a computer monitor using a pointing device. It was proposed by Paul Fitts in 1954.

Dinner table etiquette

Dinner etiquette

I've always been fascinated by etiquette, including which fork to use and where to put your napkin when you leave the table. It's like a little game, and it can make you feel more confident and empowered. So, here's a handy guide to eating dinner, illustrated by the fantastic Gemma Correll...

If you're a guest at a dinner party (pictured above), wait to start eating until the host or hostess takes his or her first bite (unless they absolutely insist that you start).A funny tip that my grandparents used to tell us: The way to sit in your chair is to pretend a cat is in front of you, a mouse is behind.Your wine and water glasses are to the RIGHT of your plate. Your bread plate is to the LEFT of your plate. If you remember that, you'll never drink someone's water or eat their bread again! (A genius tip from readers: To remember the order of the placesetting, think "BMW" -- for bread, then meal, then water.)Surprisingly, salt and pepper should be passed together, even if someone asks only for one. They're considered "married!"Never intercept a pass. For example, don't snag a roll out of the bread basket when it's on the way to someone else. (You'll just have to ask them to pass the basket right back!)Scoop your soup with your spoon tilted *away* from you. And surprise! It’s fine to tilt the bowl slightly away from you to get the last drop of soup. But never blow on your soup or food. Even if it’s piping hot!Always taste your food before putting on salt and pepper. It's considered rude to assume the food is under-seasoned before tasting it.Once you've picked up a utensil, it should never touch the table again. You want your utensils to rest fully on the edge of your plate. ("No oars!" gasp the experts.)When you are finished with your meal, your knife and fork should be placed on your plate diagonally from upper left to lower right (11 to 5 if you imagine your plate as a clock face). This is a secret code to the waiter (or host) that you’re finished.If you have to go to the bathroom—or if you’re getting up at the end of the meal—just put your napkin to the left of your plate, loosely folded.

Yay, that's it! Bon appetit!

P.S. And 8 etiquette tips for drinking wine...

(Illustrations by the amazing Gemma Correll for Cup of Jo)

Barrick gold corp - largest gold producer

Barrick Gold Corporation is the largest gold mining company in the world, with its headquarters in Toronto, Ontario, Canada; and four regional business units (RBU's) located in Australia, Africa, North America and South America. Barrick is currently undertaking mining and exploration projects in Papua New Guinea, the United States, Canada,Dominican Republic, Australia, Peru, Chile, Russia, South Africa, Colombia, Argentina andTanzania. For 2008, it produced 7.7 million ounces of gold at a cash cost of US $443/ounce. As of December 31, 2008 its proven and probable gold mineral reserves stand at 138.5 million ounces.

Supermoon

Dunning-Kruger effect

According to the Dunning-Kruger effect, the less you know, the more you think you know.

The Dunning-Kruger effect occurs when incompetent people not only perform a task poorly or incompetently, but lack the competence to realize their own incompetence at a task and thus consider themselves much more competent than everyone else. Put more crudely, they're too stupid to realize they're stupid.

If you have no doubts whatsoever about your brilliance, you could just be that damn good. On the other hand...

Biomimicry

Biomimicry borrows design solutions from the embedded intelligence within animals' bodies—chiefly from other species

FATCA

The Foreign Account Tax Compliance Act (FATCA) was enacted in 2010 as part of a broader effort to prevent U.S. persons investing in offshore entities from evading U.S. income tax. It requires non-U.S. entities to provide the IRS with information on their U.S. accountholders and investors and imposes 30% withholding on payments of U.S. source investment income to foreign entities that fail to comply. Implementing regulations were proposed in February 2012 and are expected to be finalized later this year. 

Dodd Frank act and Say on Pay

In 2010, the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) became law. Among several other purposes, the Dodd-Frank Act introduced ' Say on Pay'.

• Say on Pay. The rules initiated a required shareholder vote (non-binding), at least once every three years, to approve the compensation of the company’s named executive officers. This “say-on-pay” vote allows shareholders to assess pay practices and then render their “yes” or “no” votes.