[pjd7]

Interesting in hearing some thoughts about using roaring bitmaps stored in a bytea postgres column to represent adjacency matrixes.

I was thinking that given RDS has support for plrust and PostgreSQL's SPI I could use the fact they support croaring-rs there as a crate and build upon that.

I figure I can use that to represent many graph's with say 100s to ~100m nodes and many relations between these things. But each graph would be tenanted to a tenant (company/b2b saas use case).

I was thinking that by using plrust storing the roaring bitmap on the DB server in a bytea and using SPI, I can benefit from the minimal network overhead to mutate and query against the bitmap with croaring. Using SPI locally in the DB server I eliminate network overhead shipping that back to my application code.

PostgreSQL also gives me transaction safety to updates etc. And a bunch of support for other column base data such as my tenant ID column, some JSONB for relationship metadata to query on etc.

Basically something like https://jazco.dev/2024/04/20/roaring-bitmaps/ but on postgres. Given I need to support many tenanted graphs & we're already using citus this seems like something that is feasible at a larger scale too.

I was wondering though if I am going to need to create some operator classes to allow me to index relations a bit better (probably seems likely I think).

I am aware of https://github.com/ChenHuajun/pg_roaringbitmap but would prefer to use int64s and maybe start out on RDS instead of having to add another workload to our self hosted citus cluster/s.

Happy to be told I am fool and any insights would be nice. I am potentially going to try this out on some of our data sets we have because our product team is basically laying out a vision where they want us to have a graph powering a bunch of things.

I don't like the idea of neo4j when we're already deep into PostgreSQL for a bunch of workloads (~20+ TB table workloads etc so we have some reasonable inhouse PG experience).

Also huge thanks to the author of the blog post. I had been looking at pgRouting and wondering with a tilted head.. hmm seems like we can just use this as a graph DB. So that is also on my list to test out.