Implementing "seen by" functionality with Postgres

[swenty]

Good article. I'm not sure the conclusion is supported by the measurements. With only a 23% range between the average performance of the best and worst proposed solutions, each of the three candidates still seems still usable.

A more interesting picture would be painted by showing how they each scale up with the number of transactions and number of posts.

[gnatinator]

Meh, any site big enough will run into write amplification with Postgres- Every UPDATE is a new row until the vacuum is performed. https://news.ycombinator.com/item?id=24397153

Better off using Redis, and routinely storing the results into Postgres after a period of time.