Tested as of Ubuntu 20.04, there is no Mongo package available by default due to their change to Server Side Public License, which Debian opposed. Therefore, you have to add their custom PPA as mentioned at: docs.mongodb.com/manual/tutorial/install-mongodb-on-ubuntu/
An example where
SELECT FOR UPDATE is a good solution to an use case can be seen at: nodejs/sequelize/raw/parallel_select_and_update.js.SELECT FOR UPDATE vs/together with the SQL transaction isolation level is commented at: stackoverflow.com/questions/10935850/when-to-use-select-for-update.In particular, everything that happens in a trigger happens as if it were in a transaction. This way, you can do less explicit transactions when you use triggers. It is a bit like the advantages of SQL CASCADE.
DBMS:
Update multiple rows with different values in a single SQL query by 
Ciro Santilli 37 Updated 2025-07-16
Ciro Santilli 37 Updated 2025-07-16Demo under: nodejs/sequelize/raw/many_to_many.js.
NO way in the SQL standard apparently, but you'd hope that implementation status would be similar to UPDATE with JOIN, but not even!
- PostgreSQL: possible with
DELETE FROM USING: stackoverflow.com/questions/11753904/postgresql-delete-with-inner-join - SQLite: not possible without subqueries as of 3.35 far: stackoverflow.com/questions/24511153/how-delete-table-inner-join-with-other-table-in-sqlite, Does not appear to have any relevant features at: www.sqlite.org/lang_delete.html
ORM
- Sequelize: no support of course: stackoverflow.com/questions/40890131/sequelize-destroy-record-with-join
It is unbelievable that you can't find easily on YouTube recreations of many of the key physics/chemistry experiments and of common laboratory techniques.
Experiments, the techniques required to to them, and the history of how they were first achieved, are the heart of the natural sciences. Without them, there is no motivation, no beauty, no nothing.
School gives too much emphasis on the formulas. This is bad. Much more important is to understand how the experiments are done in greater detail.
The videos must be completely reproducible, indicating the exact model of every experimental element used, and how the experiment is setup.
A bit like what Ciro Santilli does in his Stack Overflow contributions but with computers, by indicating precise versions of his operating system, software stack, and hardware whenever they may matter.
It is understandable that some experiments are just to complex and expensive to re-create. As an extreme example, say, a precise description of the Large Hadron Collider anyone? But experiments up to the mid-20th century before "big science"? We should have all of those nailed down.
We should strive to achieve the cheapest most reproducible setup possible with currently available materials: recreating the original historic setup is cute, but not a priority.
Furthermore, it is also desirable to reproduce the original setups whenever possible in addition to having the most convenient modern setup.
Someone with enough access to labs has to step up and make a name for themselves through the huge effort of creating a baseline of amazing content without yet being famous.
Until it reaches a point that this person is actively sought to create new material for others, and things snowball out of control. Maybe, if the Gods allow it, that person could be Ciro.
Tutorials with a gazillion photos and short videos are also equally good or even better than videos, see for example Ciro's How to use an Oxford Nanopore MinION to extract DNA from river water and determine which bacteria live in bacteria for an example that goes toward that level of perfection.
The Applied Science does well in that direction.
This project is one step that could be taken towards improving the replication crisis of science. It's a bit what Hackster.io wants to do really. But that website is useless, just use OurBigBook.com and create videos instead :-)
We're maintaining a list of experiments for which we could not find decent videos at: Section "Physics experiment without a decent modern video".
Ciro Santilli visited the teaching labs of a large European university in the early 2020's. They had a few large rooms filled with mostly ready to run versions of several key experiments, many/most from "modern physics", e.g. Stern-Gerlach experiment, Quantum Hall effect, etc.. These included booklets with detailed descriptions of how to operate the apparatus, what you'd expect to see, and the theory behind them. With a fat copyright notice at the bottom. If only such universities aimed to actually serve the public for free rather than hoarding resources to get more tuition fees, university level education would already have been solved a long time ago!
One thing we can more or less easily do is to search for existing freely licensed videos and add them to the corresponding Wikipedia page where missing. This requires knowing how to search for freely licensed videos:
- Wikimedia Commons video search, e.g.: commons.wikimedia.org/w/index.php?search=spectophotometry&title=Special:MediaSearch&go=Go&type=video
- YouTube creative commons video search
Related:
- relevant University YouTube channels:
- K-12 demo projects:
- books:
- Practical approach series by Oxford University Press: global.oup.com/academic/content/series/p/practical-approach-series-pas
Minimal example: nodejs/sequelize/raw/recursive.js
More advanced SQL tree traversal examples: nodejs/sequelize/raw/tree.js
Example under: nodejs/sequelize/raw/tree.js
The highly underdocumented built-in module, that supports SQL spatial index and a lot more.
Quite horrendous as it only seems to work on geometric types and not existing columns. But why.
And it uses custom operatores, where standard operators would have been just fine for points...
Minimal runnable example with points:The index creation unfortunately took 100s, so it will not scale to 1B points very well whic his a shame.
set -x
time psql -c 'drop table if exists t'
time psql -c 'create table t(p point)'
time psql -c "insert into t select (point ('(' || generate_series || ',' || generate_series || ')')) from generate_series(1, 10000000)"
time psql -c 'create index on t using gist(p)'
time psql -c "select count(*) from t where p <@ box '(1000000,1000000),(9000000,2000000)'"Each transaction isolation level specifies what can or cannot happen when two queries are being run in parallel, i.e.: the memory semantics of the system.
Remember that queries can affects thousands of rows, and database systems like PostgreSQL can run multiple such queries at the same time.
Implementation specifics:
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact