2,487 Matching Annotations
  1. Sep 2019
    1. relational databases are often a good fit for any data that is regular, predictable, and benefits from the ability to flexibly compose information in various formats. Because relational databases work off of a schema, it can be more challenging to alter the structure of data after it is in the system. However, the schema also helps enforce the integrity of the data, making sure values match the expected formats, and that required information is included. Overall, relational databases are a solid choice for many applications because applications often generate well-ordered, structured data

      Pros and cons of relational database

    2. querying language called SQL, or structured query language, was created to access and manipulate data stored with that format

      SQL was created for relational databases

    3. Relational databases: working with tables as a standard solution to organize well-structured data

      Relational databases - oldest general purpose database type still widely used today. They comprise the majority of databases currently used in production. Initially introduced in 1969.

      They organise data using tables - structures that impose a schema on the records that they hold.

      • each column has a name and a data type
      • each row represents an individual record

      Examples:

      • MySQL
      • MariaDB
      • PostgreSQL
      • SQLite

      Diagram of relational schema used to map entities for a school

    4. database schema is a description of the logical structure of a database or the elements it contains. Schemas often include declarations for the structure of individual entries, groups of entries, and the individual attributes that database entries are comprised of. These may also define data types and additional constraints to control the type of data that may be added to the structure

      Database schema

    5. Network databases: mapping more flexible connections with non-hierarchical links

      Network databases - built on the foundation provided by hierarchical databases by adding additional flexibility. Initially introduced in late 1960s. Instead of always having a single parent, as in hierarchical databases, network database entries can have more than one parent, which effectively allows them to model more complex relationships.

      Examples:

      • IDMS

      Have graph-like structure Diagram of a network database

    6. Hierarchical databases: using parent-child relationships to map data into trees

      Hierarchical databases - the next evolution in database development. Initially introduced in 1960s. They encode a relationship between items where every record has a single parent.

      Examples:

      • Filesystems
      • DNS
      • LDAP directories

      Have tree-like structure Diagram of a hierarchical database

    7. Hierarchical databases are not used much today due to their limited ability to organize most data and because of the overhead of accessing data by traversing the hierarchy

      Hierarchical databases aren't used as much anymore

    8. The first flat file databases represented information in regular, machine parse-able structures within files. Data is stored in plain text, which limits the type of content that can be represented within the database itself. Sometimes, a special character or other indicator is chosen to use as a delimiter, or marker for when one field ends and the next begins. For example, a comma is used in CSV (comma-separated values) files, while colons or white-space are used in many data files in Unix-like systems

      Flat-file databases - 1st type of databases with a simple data structure for organising small amounts of local data.

      Examples:

      • /etc/passwd and /etc/fstab on Linux and Unix-like systems
      • CSV files
    9. Some advantages of this format

      Advantages of flat-file format:

      • has robust, flexible toolkit
      • easily managed without specialised software
      • easy to understand and work with
    10. While flat file databases are simple, they are very limited in the level of complexity they can handle

      Disadvantages of flat-file databases:

      • system that reads or manipulates the data cannot make easy connections between the data represented
      • usually don't have any type of user or data concurrency features either
      • usually only practical for systems with small read or write requirements. For example, many operating systems use flat-files to store configuration data
    1. One of the earliest interactions with a customer is to signal a lack of trust. The bartender is suggesting the customer will leave without paying.

      Show your trust to the customer

    2. I think many business owners do not consider the subconscious effects on how they manage their business

      Don't forget about the subconscious effects

    3. In another example, there is a plaza near where I work that has a number of eating options but my preferred is a sandwich place at the far end of the building. When I pull in I often look for parking in front, if there is not I might need to go to the opposite end of the plaza to find parking. While walking to the sandwich shop I pass by 3 other places to eat. I almost never make it to the sandwich shop. I always convince myself to try something different before getting to the front door of my go-to lunch spot

      That's what would happen if your customers would need to take a long walk from the other end of the parking lot

    4. the experience his customers have while visiting him was very important to him and it started when they pulled into the parking lot. In his view, they should have front row parking

      Why to park far away from your own business office

    1. "Secrecy is the first law of Magic" - from Julia Cameron's Artist's Way.Talking about your project seems to spread your energy in every direction other than towards completion.

      Inspiring comment

    2. Four different tests of 63 people found that those who kept their intentions private were more likely to achieve them

      Speaking about numbers

    3. W. Mahler found that if a person announced the solution to a problem, and was acknowledged by others, it was now in the brain as a “social reality”, even if the solution hadn’t actually been achieved
    4. Announcing your plans to others satisfies your self-identity just enough that you’re less motivated to do the hard work needed

      Tests done since 1933 show that people who talk about their intentions are less likely to make them happen

    1. Pretty much the same things as the engineering blog, but make sure to skim through the “Issues” section to see if you can find anything else interesting.

      Things to look for in open source projects

    2. What projects/products have they developed recently? And more importantly, what led them to build these things? What business challenges or goals drove the project? What technical challenges drove it?

      Things to look for in the developer's blogs

    3. The list of product(s). Is there anything similar you’ve worked on that you can show you understand the business problems and domain? Anything similar you’ve worked on where you helped make UX and/or feature decisions (where you stepped outside your developer-world bubble?). Anything similar that you had to develop a unique technical solution for? You want to show you can understand the business/product side of things and translate that into technical solutions. List of customers (company’s love to list customer logos!). While on the surface this might not seem that helpful, it can actually provide helpful information. Is there a particular type of customer they have that you have developed solutions for before? (i.e. – government, insurance, etc). Any specific customer you have built products for before? News section. Companies will often talk about new customers, recent acquisitions, and new product developments here. This will give you a sense of where the company is headed and is really useful to bring up in interviews as it shows you have an understanding of the current state of the company.

      Things to look for on company websites

    4. Things to look for are: What are recent things they’ve worked on or tools they’ve built? What are things they’re working on now? Projects/products/etc What projects/products do they mention that you would be working on? Do they mention any specific technologies you have experience with (not Node/React etc, but for example, performance testing tools -> this suggest they have a lot of traffic and they need to profile their services, something that you would be a good fit for if you have this experience) Anything they explicitly mention they need help with? Sometimes job posting will say things like “We just had a huge increase in users and need to hire another developer to help us re-architect some of our core services”.

      Things to look for in job postings

    5. At a very high level, it is:

      Better approach to look for jobs:

      Step 1: figure out what companies’ problems are: – Research company website, engineering blog, etc. to find out what these problems are

      Step 2, show how you can help solve those problems: – create your “pitch” (whether this is a resume and quick paragraph email, or something in person, approach is the same) by showing how your skills and experience will help solve their problems

    6. The job search process is a sales process – one in which you are selling your skills and experience
    1. Anki seems more common among software engineers
    2. Engineers are creatures of habit. Make reviewing your flashcard app your first work task (or the train, the toilet right before Candy Crush). Stop StackOverflowing "how do i amend my git commit" five times every month.

      Spaced repetition is a solution to googling 5 times a month the same thing

    3. Outside of medical students and language learning apps like Duolingo, spaced repetition isn't common. It's not as cool as cramming, but it works. Medical students use it to memorize those awful thousand page textbooks. Duolingo uses it because it's effective

      The most popular appliers of spaced repetition:

      1. Medical students
      2. Duolingo users
    4. But Why Option 3?

      Why spaced repetition is superior to cramming (reviewing just a week before the exam):

      1. Cramming rarely works after it passes from short-term memory. How many cram sessions do you remember from high school?
      2. Evenly spaced reminders sort-of works, but you'd have to review all your knowledge at every interval, which doesn't sound scalable/fun/have a social life.
      3. Our brains work best with exponentially spaced reminders.
    5. Spaced repetition is a remembering technique that will remind you concepts at spaced intervals to maximize memory retention efficiently

      Spaced repetition Spaced repetition

    1. in SM, learning and remembering are blended into one: you read (learn) and review (remember) at the same time. Incremental Reading is essentially “spaced repetition-ing” your reading

      Super Memo combines learning + remembering

    2. Learning = reading and understanding new things Remembering = memorizing what you learned

      Learning vs remembering

    1. 75 countries already using the technology

      75 countries already use facial recognition

    1. However, if you believe that you are indistractable, you empower yourself to respond more healthily to whatever distractions get in your way

      How to be Indistractable (summary): How to be Indistractable (summary)

    2. identity pact is another way to change your response to distractions. Your self-image has a profound impact on your behavior

      Identity pact - give yourself a new identity, like "vegetarian" to force yourself to stop eating meat

    3. price pact puts money on the line. If you stick to your intended behavior, you keep the cash. If you get distracted, you forfeit your funds

      Price pact - make an agreement with your friend that you will give him a lot of money in case you won't finish what you want to

    4. effort pact is a kind of precommitment that involves increasing the amount of effort required to do something you don’t want to do

      Effort pack is one of the examples of precommitments. You can use "Forest" app as example to help you with it

    5. you can take back your smartphone in four steps
      1. Remove needless apps.
      2. Shift the usage of mobile apps to desktop.
      3. Rearrange icons on your screen.
      4. Adjust notifications.
    6. The right approach is to ask whether the external trigger is serving you, or whether you are serving it

      Way to decide if it's better to eliminate the trigger or not

    7. research shows that ignoring a call or message can be just as distracting as responding to one

      Notifications are one of the main sources of distraction

    8. After all, the most important people in your life deserve better than the leftover time in your day

      That's influential...

    9. Go ahead and scroll through social media, but at allotted times

      Don't stress about purely working on your values. Allocate the time for the other activities, but only do them at the allocated time

    10. Turn your values into time

      Don't just talk about your values, but invest them into time

    11. Don’t pick your goals, pick your values

      Pick your values instead of goals. Otherwise others will dictate your activities and use your time. Example values:

      • being a contributing member of a team
      • being a loving parent
      • being in an equitable marriage
      • seeking wisdom
    12. “leaves on a stream” method. Imagine yourself beside a stream, on which leaves gently float by. Place each thought and negative feeling in your mind on one leaf and watch them float away

      Use "leaves on a stream" method when facing distraction. Put then on the leaves and let them float away. Apart from it:

      • identify things that prompt the distraction
      • log how you feel at that time
    13. You can’t control how you feel, but you can learn to control how you react to the way you feel.To start, you can change how you think about the bad feelings that can lead to distraction.

      We have lack of control over our feelings, but not over our reaction

    14. The truth is, we overuse video games, social media, and our cell phones not just for the pleasure they provide, but because they free us from psychological discomfort

      Root cause of human behaviour is the desire to escape discomfort

    15. The opposite of “distraction” is “traction.” Traction is any action that moves us towards what we really want. Tractions are actions, done with intent.

      Traction

    16. distractions aren’t necessarily your fault, they are your responsibility

      Learn to become indistrictable

    1. People who frequently consume artificially sweetened drinks biologically look 5-10 years older compared to those who don’t
    1. 3 lessons in branding

      3 lessons in branding:

      • “At the end of the day, brands are about trust”
      • All great brands are authentic, credible, and aspirational

        If you check all three of these boxes, there’s no reason why you can’t enter a new product vertical

      • To put your brand on steroids, attach yourself to a celebrity or influencer

    1. 16 MOOCs offered by the University of Pennsylvania through a company called Coursera. They found that completion rates averaged at around 4 percent.

      Completion rate of most MOOCs is fairly small

    2. The UT System invested $5 million in edX and committed to spending another $5 million on course development. It was in good company; Harvard University and the Massachusetts Institute of Technology had each ponied up $30 million to launch the service. Rice University, Texas’ elite private institution, also partnered with edX.

      Money invested in creation of edX

    1. Some of the best and most affordable premium laptops on the market are now shipping with Linux pre-installed. More specifically they’re shipping with Deepin

      Huawei started selling laptops with Deepin

    1. Segway was $5,000 at launch in 2001, which is a whopping $7,248 in inflation adjusted dollars. Here in 2019, cheap $200 to $300 electric scooters are basically the transformational technology the Segway was supposed to be, aren't they

      Great decrease in price over the electric scooters

    2. Did I mention there's a bluetooth connection, and an app, and it is possible to hack the M365 firmware?

      M365 scooter is not fully secure

    3. There are some challenges with electric scooters, starting with the biggest one: your local government has no idea how to regulate the darn things.

      Regulating electric scooters brings a ton of questions

    4. 46% of Uber's rides are under 3 miles

      That's why it's worth considering the use of electric scooters, to save the costs and road traffic

    5. What killed the electric scooter back then is the same thing that killed the electric car of year 2000: terrible lead-acid battery technology

      Lithium Ion batteries matured and saved the electric scooters and cars market. Back then in the year 2000, lean-acid battery was too immature

    1. it's not that there are new vulnerabilities that have been identified in the implicit flow, just that PKCE offers a more secure alternative that you should use if you have the option

      Use PKCE instead of the implicit flow if you have a chance

    2. PKCE (which stands for "Proof Key for Code Exchange" and is pronounced "pixie") was originally developed to solve a problem specific to native mobile apps using OAuth 2.0

      PKCE (Proof Key for Code Exchange) is an extension to OAuth 2.0

    3. While this has worked and continues to work for a wide range of web applications, security experts had (and continue to have) concerns that it leaves open some potential attack vectors

      Implicit flow is still simple and very secure

    4. click a button that says "Sign in with GitHub." I am then sent to GitHub to sign in and, if this is my first time, grant permissions

      The Implicit flow:

      1. The application requests authorization from the user ➡
      2. The user authorizes the request ➡
      3. The authorization server issues an access token via the redirect URI ⬅
      4. The application uses the token to call the API ➡
    1. If eating more realistic fake meat was about health, the offerings would be far lower in salt content, contain fewer calories and have a bit less dietary fat. None of them do, because the point was never to live up to the marketing of healthier eating. It was to simply act as a smooth replacement for the meat we worried about eating in our day-to-day lives

      Summary of the article. All goes down into marketing and human manipulation

    2. Most of us don't truly understand how to feed ourselves in a way that doesn’t leave us susceptible to life-threatening illnesses

      Knowing what to eat is a great mystery

    3. excessive amount of salt in one's diet has been linked in several different ways to heart disease

      Salt, just like red meat is dangerous for our heart

    4. Heart disease and cases of type 2 diabetes are on the rise, no matter where you look, and research has suggested that cutting red meat and processed meats (like bologna and other deli meats) might help people facing these conditions

      Research suggests that red meat and processed meat are a cause of heart disease and cases of type 2 diabetes

    5. In fact, when you start to compare all of these offerings to their meat-based counterparts, you realize it’s the same story no matter what brands you’re talking about — you might possibly save a few calories or carbs, but you'll probably get way more salt.

      Meatless (plant-based) burgers may have a little less calories, but more salt

    1. By nine to ten years of age, children’s sensitivity to the distinction between sarcasm and verbal irony highlights their impressive understanding of how people’s feelings are affected by others’ speech

      9-10 years old kids start to distinct between sarcasm and irony

    1. these signs will help you prevent burnout before it starts – or work to fix it if you need a way out.

      Ways to beat burnout:

      1. Take less job responsibilities
      2. Identify what gives you energy, and what drains it
      3. Manage your digital distractions
      4. Don't give all of your energy to work
      5. Just say "no" to too many projects
      6. Make self care a priority
      7. Lean on your support network
      8. Manage well
    2. People who feel burned out at work find their home life is more likely to suffer too. This may be because when jobs get more demanding, people put more time and resources into them, often at the expense of their private lives.

      Burnout also affects your private life

    3. 57% reported feeling like they need to check in with work – even when they are on vacation

      Need to be "on the call" even after the work is one of the greatest burnout symptoms

    4. these symptoms suggest that you may be more than stressed:

      Symptoms of a burnout:

      • You’ve become cynical or critical at work
      • You drag yourself to work and have trouble getting started
      • You’re irritable or impatient with co-workers, customers or clients
      • You lack the energy to be consistently productive
      • You find it hard to concentrate
      • You lack satisfaction from your achievements
      • You feel disillusioned about your job
      • You use food, drugs or alcohol to feel better or to simply not feel
      • Your sleep habits have changed
      • You’re troubled by unexplained headaches, stomach or bowel problems, or other physical complaints
    5. when the feeling of being completely overwhelmed at work persists, it can spiral into burnout – a growing epidemic with serious consequences for your health and your career.

      How burnout starts and what it is

    1. XMATCH which has a similar signature to XLOOKUP but returns the index of the matching item. XMATCH is both easier to use and more capable than its predecessor MATCH.   XMATCH(lookup_value,lookup_array,[match_mode],[search_mode])

      XMATCH is another upcoming Excel function

    2. While VLOOKUP was widely used, it has several well-known limitations which XLOOKUP overcomes: 

      XLOOKUP overcomes 6 VLOOKUP's issues:

      1. Defaults to an "approximate" match.
      2. Does not support column insertions/deletions.
      3. Cannot look to the left.
      4. Cannot search from the back.
      5. Cannot search for next larger item.
      6. References more cells than necessary.
    3. XLOOKUP(lookup_value,lookup_array,return_array)   lookup_value: What you are looking for lookup_array: Where to find it return_array: What to return

      XLOOKUP will replace VLOOKUP and HLOOKUP excel functions used since 1985

    1. you don’t have to learn alone. In fact, it is the uniqueness of the people with which you learn and the discussions you have together that make what you learn unforgettable

      Team work applies also into learning

    2. being able to communicate what you’ve learned is one of the main skills that differentiates a good developer from a great one (IMHO).

      Know how to explain what you just learned

    3. When facing procrastination, think of process over product. I often procrastinate when I’m overwhelmed by the thought, “Ok, I have to get X done”. Instead, it can be beneficial to think, “Ok, I will spend an hour on X” — which isn’t overwhelming, doesn’t require a long breakdown of tasks, and gets me started (90% of the battle)

      Solution to procrastination

    4. Know when to apply a particular concept is as important as knowing how.

      Use cases are more important than we think of

    5. Spread it out over many sessions and over many different modes of learning.

      Don't learn everything in a single session!

    6. test yourself as you’re encountering new material. Recall is a simple example of this mini-testing.

      Recall = mini-testing

    7. taking a couple minutes to summarize or recall material you are trying to learn

      It's worth to take the time to ponder

    8. Recently, I found this great application called Highly (you should use this!). They make it really simple to highlight any article that I’m reading on the web using a Chrome extension.

      This inspired me to make a research of similar applications (such as Liner), and finally end up with hypothes.is

    9. Highlighting or underlining are also techniques that often lead to this illusion of learning. On the other hand, brief notes that summarize keys concepts are much more effective.

      Indeed… Therefore, let's leave a note here :)

    10. First, survey and priming — this involves scanning a book or the syllabus of a course, for example, to get a general idea of the bigger picture. Second, observe an example. Then, do it yourself. And, finally, do it again and again in different contexts.

      Chunk the knowledge

    11. take breaks, meditate, think about other things, and give yourself plenty of time in both modes.

      Give yourself some free time while learning