[hodgesrm]

This is an excellent article. I like the way the author builds up in steps to eventual consistency between source tables and their materialized views. It was fun to guess the next step.

I do have one question: how does the algorithm described in the article work when the source table is spread across multiple servers, say in multiple shards? Can TimescaleDB maintain materialized views on each shard and then run a query that reconciles them?

Edited: clarification

[djk447]

NB: Post author

So we thought about doing something like that with multinode where each of the nodes would maintain their own materialization but abandoned it for that very reason it’s very, very difficult to maintain any sort of consistency guarantees in that case, or even to reason about it.

Instead we use the access nodes as coordinators to do the materialization. right now the materialization only exists on the access node but there’s no reason we couldn’t send it back out to the data nodes, you just need a coordination point to start a distributed transaction to have some semblance of a guarantee.

[djk447]

And glad you liked the article!

[hodgesrm]

It was excellent. I work on ClickHouse and wrote something similar a while back for ClickHouse mat views. [0] It was not nearly as good, hence the appreciation.

Don't know if you do talks but I have a couple opportunities coming up at open source events. We like hearing about what people are doing outside of ClickHouse.

[0] https://altinity.com/blog/clickhouse-materialized-views-illu...