I went snorkeling with my wife and 5 yo son during our vacation to Lombok earlier this year. Even though I was not so bad as swimming, I found out that snorkeling requires a bit of familiarization in order to fully enjoy it. However the wife and son were also enjoying it so much despite the fact that they can't swim (they wore life jackets while snorkeling). To make a long story short, we finished our vacation wanting to do more snorkeling and me wondering how a proper snorkeling activity should be like. That's how I found about freediving while surfing the internet, and I am so amazed by its simplicity yet, at the same time, physically and mentally demanding nature. I'm starting to think about learning freediving, even if it's just in the most recreational sense of it. So here are some useful resources I found about freediving. As usual, I put it here for my personal reference, and hope it can be beneficial to others researching about the same topic as well.
Freediving (also free diving,free-diving) is a form of underwater diving that relies on a diver's ability to hold his or her breath until resurfacing rather than on the use of a breathing apparatus such as scuba gear.
More complete information can be found on the Wiki page. Starting Out
Taking a course to begin with is highly encouraged if not a must. However, DeepBlue.com has a comprehensive thread on How to start Freediving for those looking for preliminary information regarding the sport. Books covering aspects of freediving are also available. Two of the most well known are Manual of Freediving: Underwater on a single breath and Underwater foraging - Freediving for food authored by Umberto Pelizzari and Ian Donald, respectively. I found these 2 YouTube videos, both featuring each expert, explaining the basics of learning how to freedive.
Yoga (Relaxation & Breathing)
Freediving is closely related to apnea (breath holding) and relaxation. Freediving can also be considered as an extreme sport, but in contrast with the others, instead of rushing your adrenaline, you need to be in a calm and relaxed state of mind in order to freedive well. This is where yoga breathing and relaxation techniques come into play, and these 2 links should give you some idea:
Having work with Oracle databases, I regularly stumble upon incorrectly interchanged terms. The 1st is database and instance. A database is a collection of data. An Oracle database holds its data in a coordinated set of files stored on disk. An instance, on the other hand, is a collection of Oracle background processes and shared memory structures. Normally a database is mounted and opened by one instance, this misleads some people into perceiving database and instance as the same thing while fundamentally they are not.
The 2nd is user and schema. A database consists of multiple users that one can connect to. A schema is the set of objects (tables, views, indexes, etc.) that belongs to a user account. So again, these are essentially different.
My prejudice for these misuse is that when one knows a technical jargon, one will have the tendency to overuse it, in hope to be perceived as technologically advanced. "Database" and "user" are too common and sound less technical compared to "instance" and "schema", but these terms refer to different meanings. Let's use them appropriately.
