ethanseal

4 ms·

1.
Subtypes and status-dependent data: pure relational approach(minimalmodeling.substack.com)
2 points by ethanseal 8mo ago|0 comments
2.
Two ways to crack a walnut, per Grothendieck (2025)(shreevatsa.net)
54 points by ethanseal 9mo ago|19 comments
3.
Faking Dot Density on a Map(ethanseal.com)
5 points by ethanseal 10mo ago|0 comments
4.
by ethanseal 1y ago
Exactly the same one from what I see: https://github.com/ethan-seal/ors_expensive/blob/main/explai... Given the buffer reads seem close to yours, I believe it's page cache.
5.
by ethanseal 1y ago
When you say cold cache, did you clear the os page cache as well as the postgres buffercaches? After setup.sql, the cache will be warmish - I get 4ms on the first run. I'm using postgres 17.5 See https://github.com/etha
6.
by ethanseal 1y ago
Materialized views in Postgres don't update incrementally as the data in the relevant tables updates.^1 In order to keep it up to date, the developer has to tell postgres to refresh the data and postgres will do all the work from scrat
7.
by ethanseal 1y ago
GIS is underrated. This is awesome! Have you looked into speaking with the various SHPOs in each US State/Territory? I've worked with several of them a fair bit and they have a ton of old maps hidden internally. Especially for s
8.
Use the Index, Luke – SQL Indexing and Tuning(use-the-index-luke.com)
20 points by ethanseal 1y ago|0 comments
9.
by ethanseal 1y ago
I think having a way to build statistics on the join itself would be helpful for this. Similar to how extended statistics^1 can help when column distributions aren't independent of each other. But this may require some basic materializ
10.
by ethanseal 1y ago
Highly recommend https://use-the-index-luke.com/ It's very readable - I always ask new hires and interns to read it.
11.
by ethanseal 1y ago
Cool. I'll have to read up on that.
12.
by ethanseal 1y ago
For sure, there's definitely a lot of cool techniques (and I'm not aware of all of them)! And the first example is very much contrived to show a small example. I'm not super familiar with the term index merge - this seems to
13.
by ethanseal 1y ago
Gotcha, I misunderstood your comment. The multiple counts is a definitely very contrived example to demonstrate the overhead of BitmapOr and general risk of sequential scans.
14.
by ethanseal 1y ago
Absolutely. Though I don't recall seeing multiple sequential scans without a self-join or subquery. A basic filter within a sequential scan/loop is the most naive/simplest way of performing queries like these, so postgres fal
15.
A SQL Heuristic: ORs Are Expensive(ethanseal.com)
170 points by ethanseal 1y ago|79 comments