> 'Why can't we just store this data on the shards in PostgreSQL, next to the swipes?'. The data itself would be microscopic in comparison and the additional load would also be microscopic in comparison to what these servers were already doing.
I'm assuming based on the rest of the article that the author and team knew what they were doing, but if you aren't familiar with Postgres' UPDATE strategy and HOT updates [0], you should familiarize yourself before attempting this, otherwise, you're going to generate a massive amount of WAL traffic and dead tuples at scale.
I'm assuming based on the rest of the article that the author and team knew what they were doing, but if you aren't familiar with Postgres' UPDATE strategy and HOT updates [0], you should familiarize yourself before attempting this, otherwise, you're going to generate a massive amount of WAL traffic and dead tuples at scale.
[0]: https://www.postgresql.org/docs/current/storage-hot.html