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by didgetmaster 1423 days ago
Storing Json data into a highly structured RDBMS table can be problematic if any document contains arrays or nested documents.

I built a new general-purpose data management system that uses key-value stores that I invented to attach meta-data tags to objects. These key-value stores can also be used to create relational tables.

Because each table is basically a columnar store, I can map multiple values to each row key to create a 3D table. It seems ideal for importing Json data where any item in a document can be an array of values. I am trying to figure out how useful this system might be to the average DBA or NoSql user.

See a quick demo at https://www.youtube.com/watch?v=1b5--ibFhWo

2 comments

what I'm saying is, use the relational DB for OLTP, but export in a JSON document format to NoSQL in whatever document shapes are efficient for various services. And that can be multiple different shapes generated from the same set of relational "ground truth", if various services need different "views" to run efficiently.

The idea is you always have a relational "source of truth" and optimize that for OLTP, but also get the scalability benefits of documents/microservices/etc by having data already pre-coalesced/pre-digested into your correct format(s), so you're not doing complex analytical/window/aggregation queries on the RDBMS for every request. You run the analytical queries once, convert the result to json, and store that in the NoSQL.

Of course you still potentially have some "sync time" between the OLTP and the final commit to all the various nosql collections... unless you hold OLTP locks until everything is synced, which would be excessive. But this goes back to CAP and there's no magic wand for that - you can either put everything inside the RDBMS and take the performance hit, or you can have external nosql read replicas and accept the inconsistency due to the sync time, or you can hold locks until both systems are consistent at the cost of "availability" (updatability).

How different is this from using pg’s jsonb field type? Which is also queryable.

What are the advantages/disadvantages? Or what am I misunderstanding?

To be honest, I haven't played around with the jsonb feature of pg enough to know which is better. I do know that the queries of data in my system average about 10x faster than regular pg tables for the same data set. Also my tables do not need a separate indexing step in order to achieve maximum speed for any query. Do you have a data set in pg you created using jsonb? If you want to try my system, the beta is available for free download at: https://didgets.com/download