34 Matching Annotations
  1. Oct 2023
    1. UUID Version 7 (UUIDv7) is a time-ordered UUID which encodes a Unix timestamp with millisecond precision in the most significant 48 bits. As with all UUID formats, 6 bits are used to indicate the UUID version and variant. The remaining 74 bits are randomly generated. As UUIDv7 is time-ordered, values generated are practically sequential and therefore eliminates the index locality problem.

      0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | unix_ts_ms | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | unix_ts_ms | ver | rand_a | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |var| rand_b | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | rand_b | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

  2. Aug 2023
    1. If you are using UUIDs instead of integers as the primary key on your models, you should set Rails.application.config.generators { |g| g.orm :active_record, primary_key_type: :uuid } in a config file.
  3. Oct 2022
  4. Jun 2022
    1. Creating GUID/UUID in Javascript using ES6 Crypto APIWe can use JavaScript ES6’s crypto API to generate GUID/UUID at the client side.crypto API comes up with a method called getRandomValues() which is used to generate a Universally Unique IDentifier as shown below

      js function CreateUUID() { return ([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g, c => (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16) ) }

  5. Jan 2022
    1. There are officially 5 types of UUID values, version 1 to 5, but the most common are: time-based (version 1 or version 2) and purely random (version 3). The time-based UUIDs encode the number of 10ns since January 1st, 1970 in 7.5 bytes (60 bits), which is split in a “time-low”-“time-mid”-“time-hi” fashion. The missing 4 bits is the version number used as a prefix to the time-hi field.  This yields the 64 bits of the first 3 groups. The last 2 groups are the clock sequence, a value incremented every time the clock is modified and a host unique identifier.

      There are 5 types of UUIDs (source):

      Type 1: stuffs MAC address+datetime into 128 bits

      Type 3: stuffs an MD5 hash into 128 bits

      Type 4: stuffs random data into 128 bits

      Type 5: stuffs an SHA1 hash into 128 bits

      Type 6: unofficial idea for sequential UUIDs

    2. Even though most posts are warning people against the use of UUIDs, they are still very popular. This popularity comes from the fact that these values can easily be generated by remote devices, with a very low probability of collision.
  6. Jun 2021
    1. We explore them in other chapters and in particular in Macroeconomic Policy Around the World.

      Reference to OS 19 (not currently mapped in our AL)--remove?

    2. The European Union has strong programs to invest in scientific research. Researchers Abraham García and Pierre Mohnen demonstrate that firms who received support from the Austrian government actually increased their research intensity and had more sales. Governments can support scientific research and technical training that helps to create and spread new technologies. Governments can also provide a legal environment that protects the ability of inventors to profit from their inventions.

      From OS

    3. Scientific Research

      This would be an excellent place to mention the US funding of COVID vaccine research--maybe a link to learning after this card?

    4. For example, saver's credits make certain retirement savings tax-exempt, meaning savers get to keep more of the interest they earn on savings investments.

      This example is pulled from Giacomo's slides. Possible replacement: education fund accounts? (Same concept of tax-exemption, less common)

    5. In the United States and many other countries, the government taxes gains from private investment. Low capital gains taxes encourage investment and so also economic growth.

      This sentence is from OS

    6. Government Action: Education

      First paragraph is Giacomo adaptation, second paragraph is OS text

    7. EducationSavings and investmentScientific researchHealthcareInternational tradeInfrastructureSpecial economic zones

      This is a combo of Giacomo's list and OS's list. I've devoted one explanation card to each item on this list. Education, savings/investment, and scientific research are featured by both Giacomo & OS; we may want to cut some of the others

    8. A Healthy Climate for Economic Growth

      From OS 7.3

    9. empirical evidence

      It would be great if we could pull empirical evidence to support this

    1. Capital Deepening

      Start of OS content (late 7.3), runs to the end of the section

    2. image

      Caption: "Figure 7.6 Physical Capital per Worker in the United States The value of the physical capital, measured by plant and equipment, used by the average worker in the U.S. economy has risen over the decades. The increase may have leveled off a bit in the 1970s and 1980s, which were, not coincidentally, times of slower-than-usual growth in worker productivity. We see a renewed increase in physical capital per worker in the late 1990s, followed by a flattening in the early 2000s. (Source: Center for International Comparisons of Production, Income and Prices, University of Pennsylvania)"

    3. image

      Caption: "Figure 7.5 Human Capital Deepening in the U.S. Rising levels of education for persons 25 and older show the deepening of human capital in the U.S. economy. Even today, under one-third of U.S. adults have completed a four-year college degree. There is clearly room for additional deepening of human capital to occur. (Source: US Department of Education, National Center for Education Statistics)"

    4. explosive growth

      Key term?

    5. .

      In the lecture notes, Giacomo says "The logic behind decreasing returns is that, if K increases while holding L fixed machines per worker and worker productivity falls." I don't have great clarity on what "worker productivity falls" truly means and don't want to put something incorrect--fill in once lecture videos are out

    6. hen a new technology is created to increase productivity, many firms can benefit from the new technology aside from the firm that created it.

      This example is taken from lecture (the pollution example is from OS Micro)

    7. Spillover

      We should actually define spillover somewhere

    8. nternal forces create the potential for a production function with increasing returns.

      This is a shortened version of the full definition to avoid vocab words we haven't defined yet

    9. Growth Comes From Within

      Starting off with Giacomo's slide content

    1. website

      This link to learning is a NYT article behind a paywall, we should look for a replacement that is truly free

    2. Lesson Text

      For this card & the others in this section--if we keep capital deepening defined in the later section, we should revise the wording to avoid referencing capital deepening or heavily edit this section

    3. image

      Figure 7.7 Capital Deepening and New Technology Imagine that the economy starts at point R, with the level of physical and human capital C1 and the output per capita at G1. If the economy relies only on capital deepening, while remaining at the technology level shown by the Technology 1 line, then it would face diminishing marginal returns as it moved from point R to point U to point W. However, now imagine that capital deepening is combined with improvements in technology. Then, as capital deepens from C1 to C2, technology improves from Technology 1 to Technology 2, and the economy moves from R to S. Similarly, as capital deepens from C2 to C3, technology increases from Technology 2 to Technology 3, and the economy moves from S to T. With improvements in technology, there is no longer any reason that economic growth must necessarily slow down.

    4. Arguments Favoring Convergence

      Back to OS 7.4

  7. Nov 2018
  8. Jul 2016
    1. Resize2fs did the trick and you can see that we have 49G partition now.

      swapon -a is missing, which means /etc/fstab has to be updated with eventual new partition UUIDs.