Top all-time · #25841
Ludwig Hähne
Personal blog · pankrat.github.ioprogrammingweb
Ludwig Hähne writes Another web backend developer Blog, a personal blog at pankrat.github.io about programming and web. Since 2018, 3 different Hacker News readers have linked it 3 times. The last post was in 2015, but the archive is still widely read.
Too few sampled comments (3) to say how often HN recommends it.?
Why HN links it
HN commenters link this blog for its posts on avoiding downtime in Django and Postgres schema migrations, including a explanation of database locks and why Django migrations need manual SQL for default values.
Summarised by Claude from a sample of 3 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Most-linked posts?
- /2015/django-migrations-without-downtimes/2 people · 2 mentions · first linked 2025-05-18
What Hacker News says?
>Migrate database to new schema... spin up new instance Sadly this is more of a pain in Django, since it does not write default values to the database. To be able to safely run the migration first, one must manually rewrite the SQL for the migration. [1] [1]: http://pankrat.github.io/2015/django-migrations-without-down...
Comment linking /2015/django-migrations-without-downtimes/
on “Managing database schema changes without downtime”These are database locks, which means that depending which arrives first, the later transaction has to wait till the first one finishes to complete. These locks are about SQL commands and which commands can run concurrently with the others. There's a graph here of how that looks like https://pankrat.github.io/2015/django-migrations-without-dow... Usually for maximum performance (minimum latency, maximum throughput)…
Comment linking /2015/django-migrations-without-downtimes/
on “Pglocks.org”This is not specific to Django, but to any project using a database. Here's a list of a couple quite useful resources I used when we had to address this: * https://github.com/tbicr/django-pg-zero-downtime-migrations * https://docs.gitlab.com/development/migration_style_guide/ * https://pankrat.github.io/2015/django-migrations-without-dow... * https://www.caktusgroup.com/blog/2021/05/25/django-migration... * https://…
Comment linking /2015/django-migrations-without-downtimes/
on “Notes on Starting to Use Django”