citus VS hydra

I see they don't mention Citus (https://github.com/citusdata/citus), which is already a fairly mature native Postgres extension. From the details given in the article, in sounds like they just reimplemented it.

I wonder if they were unaware of it or disregarded it for a reason —I currently am in a similar situation as the one described in the blog, trying to shard a massive Postgres DB.

It is possible, if you pay for it. You can do Multi-AZ Clustered Instances in RDS, where you get the benefits of Multi-AZ failover with traffic sharing.

If you can run your own infra – at least on an EC2 level – you can do things like Citus [0] for Postgres, which is about as close to "just add database nodes" as you'll get.

[0]: https://www.citusdata.com/

So while searching for something like this for postgres I came across citus. Any one know how that stacks up?

https://github.com/citusdata/citus

References: CitusDB

Don't feel bad, lots of people get bitten by not reading all the way down to the bottom of their readme: https://github.com/hydradatabase/hydra/blob/v1.1.2/README.md... While Hydra may very well license their own code Apache 2, they ship the AGPLv3 columnar which to my very best IANAL understanding taints the whole stack and AGPLv3's everything all the way through https://github.com/hydradatabase/hydra/blob/v1.1.2/columnar/...

Columnar store PostgreSQL extension exists, here are two but I think I’m missing at least another one:

https://github.com/citusdata/cstore_fdw

https://github.com/hydradatabase/hydra

You can also connect other stores using the foreign data wrappers, like parquet files stored on an object store, duckdb, clickhouse… though the joins aren’t optimised as PostgreSQL would do full scan on the external table when joining.

New column store alternative : https://github.com/hydradatabase/hydra

HN: https://news.ycombinator.com/item?id=37571974

some previous discussions:

https://news.ycombinator.com/item?id=37247945

https://news.ycombinator.com/item?id=36987920

and a relevant observation is that there are actually multiple license files in the repo so the consumer should read their explicit licensing section of the readme <https://github.com/hydradatabase/hydra#license> since the GitHub sidebar is misleading

Hydra DB Link to Github -> Worked well for aggregated query usecases but not for queries that build reports. Also, data insertion and updation is abyssmal on columnar dbs.

There's a lot of experience about db operation and how to approach MVCC encoded in PostgreSQL that shouldn't be underestimated.

[0]: https://github.com/hydradatabase/hydra

And just like last time, watch out for the misleading GitHub license detector because it's not entirely Apache as the GitHub summary claims but rather *some* is Apache and buried in the interior is some AGPL stuff: https://github.com/hydradatabase/hydra#license