RMarcus

5 ms·

1.
by RMarcus 2mo ago
You can also interpret each value in Perlin noise as a vector in a flow field to make some interesting and smooth animations reminiscent of older MacOS desktop wallpapers: https://rmarcus.info/blog/2018/03/04&
2.
by RMarcus 5mo ago
I've got emacs keybinds in my muscle memory and Zed works well for me, although there's no kill ring and the macro system is nothing like emacs. The former will be added at some point (there's an open PR), but I do not expect
3.
by RMarcus 2y ago
This is awesome, thanks for creating this. I've had to write some absolutely wonky scripts to dump a PostgreSQL database into Parquet, or read a Parquet file into PostgreSQL. Normally some terrible combination of psycopg and pyarrow, w
4.
by RMarcus 2y ago
Looks like he got a master's degree from UIUC and did some research on FFT implementations. Seems to have been successful. What makes you say he was 'considered a "bad student"'? (This is a genuine question. I'
5.
by RMarcus 2y ago
Depends! If you double the number of keys and you double the number of bins (load factor stays constant), then the problem becomes much worse very quickly. If you double the number of keys and you double the size of each bin (load facto
6.
by RMarcus 2y ago
This is my post from 2018 (I didn't submit it to HN), and it could definitely use a "here's what practical systems do" update! I'll put it on the TODO list... Your point about systems dealing with a relatively small
7.
by RMarcus 2y ago
I'm curious to hear a bit more of your opinion. For example, I'm surprised that syscall latency is something near the top of your list. I think the usual wisdom in the DB community is that the cost models are mostly fine, but the
8.
by RMarcus 2y ago
PostgreSQL has coarse-grain query hints (like `enable_hashjoin`), and the excellent `pg_hint_plan` extension allows you to specify a complete or partial execution plan: https://github.com/ossc-db/pg_hint_plan
9.
by RMarcus 2y ago
It is certainly possible that the plans are similar, and that improvements to the execution engine are being measured. The join order benchmark was designed to test optimizer quality. It is worth noting that in addition to trying to measu
10.
by RMarcus 2y ago
I totally agree -- I picked the latest version for each major version using the semver interpretation of the version numbers, which is not how PostgreSQL has traditionally done major version numbers (i.e., PG 8.2 and 8.1 are different major
11.
by RMarcus 2y ago
I'm the author of the blog post. "Tail latency has improved by YMMV for everything else" => yes, I think that's a valid (but conservative) read. Of course, in many (most?) applications, tail latency is very important.
12.
by RMarcus 3y ago
This is the main motivation behind learned "steering" query optimizers: even if a DBA finds the right hint for a query, it is difficult to track that hint through data changes, future DB versions, and even query changes (e.g., if
13.
by RMarcus 3y ago
Just wanted to say thank you! This extension was critical to a bunch of my research (and now my lab's research as well). Being able to control fine-grained elements of each plan while letting the PG planner "do the rest" has
14.
by RMarcus 3y ago
Ah, I missed that this requires WAL mode -- indeed, if WAL is used, one transaction should always be able to make progress.
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by RMarcus 3y ago
My reading is that no deadlocks should be possible since there is only one lock (pages are "locked" optimistically, meaning that the tx is aborted if the page has changed). "Live locks" are possible, where two repeatedly
16.
by RMarcus 4y ago
Thanks for the first-hand information! I was also curious about this. > This is not a course everyone enrolls in. This is the ticket -- at both the University of Arizona and MIT, I've seen a group of folks graduate with a CS degree
17.
by RMarcus 6y ago
We recently published a comparison of learned indexes (including RadixSpline and the PGM index posted yesterday)in VLDB: https://vldb.org/pvldb/vol14/p1-marcus.pdf
18.
by RMarcus 6y ago
We produced a detailed comparison of such "fitting" and "learning" techniques, available here: https://vldb.org/pvldb/vol14/p1-marcus.pdf (Thomas Neumann, one of authors of the blog post, is a
19.
by RMarcus 6y ago
Check out work by Jialin Ding and Vikram Nathan, they both work on multi-dimensional learned index structures. https://arxiv.org/pdf/2006.13282.pdf
20.
by RMarcus 6y ago
https://rmarcus.info I mostly post interactive or semi-narrative explanations of technical topics I find interesting. 1-3 posts per year.
21.
by RMarcus 7y ago
My experience is entirely different -- writing HPC code for supercomputers at Los Alamos National Lab (on and off for 5 years) made me a true Rust believer. One of the things I spent the most time on with Fortran / C++ codes was debugg
22.
by RMarcus 8y ago
This would be considered absolutely batshit at all three of the R1 research universities I've been around, which spans a significant range of prestige. I think it goes to show how much variance there are in PhD programs. I frequently a
23.
by RMarcus 8y ago
Doh! Guess I should've checked. I didn't make it to Rio last year... Figured I was gonna miss a bunch of good stuff.
24.
by RMarcus 8y ago
I've only read part of it, but it seems great so far! I always appreciate the clarity and practicality y'all at the JGL take. I'm amazed that the implementation was under 1500 LOC! Was that the research prototype or the shipp
25.
by RMarcus 8y ago
I worked at Los Alamos for several years, and wore a TLD (dosimeter, radiation detection device). The only two times mine was ever "triggered" was when I left it on at the dentist (x-ray) and at the airport (x-ray). It's in
26.
by RMarcus 8y ago
It's worth noting that the computer science community (at least in systems and machine learning) have already made some strides in this direction. Systems conferences like VLDB and CIDR post the proceedings online for free (and most IC
27.
by RMarcus 8y ago
It seems to have just come back up... at least my VM is responding.
28.
by RMarcus 8y ago
The move does seem rather troubling, considering the history of Microsoft. Linux seems like it's a little too big for "extinguish," and th GPLv2 should provide some defense against nefarious "extend"ing... But then
29.
by RMarcus 9y ago
Very cool! I wrote something similar, but it only renders lines. https://rmarcus.info/blog/2017/10/23/humanlines.html
30.
What Happens to Us Does Not Happen to Most of You(sigarch.org)
265 points by RMarcus 9y ago|229 comments

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