Feels a little weird, given that there is an easy closed formula for the solutions.
Readit NewsUpitor commented on Mathematician Finds Easier Way to Solve Quadratic Equations popularmechanics.com/scie... · Posted by u/quantummagic
Upitor commented on Apache Iceberg now supports geospatial data types natively wherobots.com/apache-iceb... · Posted by u/Mosarwat
I’m super exited about the planned support for multidimensional data, I know zarr is there but a long term storage format other than netcdf would be interesting maybe also something to replace grib, geotiff etc to share files
Where do you see the upcoming support for multidim data? Link?
Upitor commented on Show HN: Gribstream.com – Historical Weather Forecast API gribstream.com... · Posted by u/ElPeque
In my experience, NWP data is big. Like, really big! Data over HTTP calls seems to limit the use case a bit; have you considered making it possible to mount storage directly (fsspec), and use fx the zarr format? In this way, querying with xarray would be much more flexible
Dead Comment
Wind turbines, the big ones, regulate themselves to turn in sync with the grid. The adjust thier blades as needed to keep pace/power. That's why huge fields of them all turn in perfect lockstep.
They are still not syncing directly to the AC grid. They are not going 50 rounds per second
Upitor commented on SQL language proposal: JOIN FOREIGN gist.github.com/joelonsql... · Posted by u/JoelJacobson
Nice example! The join you describe would remain as a JOIN ON.
This is per design. Quote from the proposal:
"The idea is to improve the SQL language, specifically the join syntax, for the special but common case when joining on foreign key columns." ... "If the common simple joins (when joining on foreign key columns) would be written in a different syntax, the remaining joins would visually stand out and we could focus on making sure we understand them when reading a large SQL query."
So, the special non-equal based join condition you describe, would become more visible, and stand out, allowing readers to pay more attention to it.
The hypothesis is most joins are made on foreign key columns, so if we can improve such cases, a lot can be won.
I see. I should have read the article more carefully :-)
Upitor commented on SQL language proposal: JOIN FOREIGN gist.github.com/joelonsql... · Posted by u/JoelJacobson
In my opinion this proposal seems only to consider simple cases, but there are many not-so-simple relationsship types:
Consider a ‘sales’ table which includes columns [time] and [sold_by_employee_id], and a periodized ‘employee’ table which includes columns [employee_id], [valid_from] and [valid_to] columns. There is a perfectly valid relationsship between the two tables, but you cant join them using only equal-statements (you need a between-statement as well)
Also, consider a ‘sales’ table with multiple references to a ‘calendar’ table: [shipped_date], [order_date], [received_date]
Upitor commented on SQL language proposal: JOIN FOREIGN gist.github.com/joelonsql... · Posted by u/JoelJacobson
In my opinion this proposal seems only to consider simple cases, but there are many not-so-simple relationsship types:
Consider a ‘sales’ table which includes columns [time] and [sold_by_employee_id], and a periodized ‘employee’ table which includes columns [employee_id], [valid_from] and [valid_to] columns. There is a perfectly valid relationsship between the two tables, but you cant join them using only equal-statements (you need a between-statement as well)
Upitor commented on The Guide to Data Versioning lakefs.io/data-versioning... · Posted by u/blackp1nk
The author makes a case against using “valid_from”/“valid_to” columns on your table. But in my experience, that is the only viable solution. Fx joining an employee-table and a department-table needs to take into account when an employee was in which department. How would do that with some git-like version control for data? That might be useful for some machine learning training dataset, but in an operational system? No thanks
Upitor commented on Ask HN: Possible to pivot into ML research career without a PhD? · Posted by u/purplerabbit
If he wants to do ML research, why doesn’t he want to do a PhD program? I dont think you can get both: if you do research, there is less focus on making operational software. If you make operational software, there is less focus on doing research. Find out what you really want to do, and go with that.