I’ve seen the term polyglot persistence floating around Redgate a bit recently in the marketing department. I haven’t really seen this term anywhere, and I wonder if you have. If you have, drop a comment.
The definition is based on the polyglot programming, where you write an app using multiple programming languages. I don’t know a lot of people who do that, and if you do, let me know. I guess some do, since I’ll see things like HTML+C#, or maybe something like Blazor + C#.
In any case, the idea seems to be that you use multiple databases to satisfy your requirements. A few examples might be:
- SQL Server for most data, Redis to cache shopping carts
- Oracle for most data, ElasticSearch for full-text searching
- PostgreSQL for profiles and leaderboards, MongoDB for real-time game actions
I’ve tended to showcase NoSQL + Relational here, but I have seen a few people using two relational stores or two NoSQL stores because it suits their needs. The really common additions (for me) are some type of NoSQL store for performance with more stable, long term data in relational.
I don’t think this covers the relational for OLTP and something else for OLAP/warehousing, as that seems to be an ETL/ELT/transfer of data over time for a different purpose rather than for the same application, but I guess it could cover that.
I think Polyglot Persistence is a good idea, especially when you have complex requirements that aren’t easily solved with one database, even when you have in-memory or search/graph features in your database. Often those don’t perform as well as specialized systems, though there is a level of complexity and the challenge of ELT/ETL’ing the data to/from the second system.
Evaluate carefully, PoC, and test at scale before you decide this is worth the trade.