[IggleSniggle]

In regards to Elasticsearch, you basically opt-in to which behavior you want/need. You end up in the same place: potentially losing some data points or introducing some "fuzziness" to the results in exchange for speed. When you ask Elasticsearch to behave in a guaranteed atomic manner across all records, performing locks on data, you end up with similar constraints as in a RDBMS.

Elasticsearch is for search.

If you're asking about "what if you use an RDBMS as a pointer to Elasticsearch" then I guess I would ask: why would you do this? Elasticsearch can be used as a system of record. You could use an RDBMS over top of Elasticsearch without configuring Elasticsearch as a system of record, but then you would be lying when you refer to your RDBMS as a "system of record." It's not a "system of record" for your actual data, just a record of where pointers to actual data were at one point in time.

I feel like I must be missing what you're suggesting here.

[altdataseller]

Having just an Elasticsearch index without also having the data in a primary store like a RDMS is an anti-pattern and not recommended by almost all experts. Whether you want to call it a “system of record”, i wont argue semantics. But the point is, its recommended hacing your data in a primary store where you can index into elasticsearch.

[zasdffaa]

Have you a link for this? Never heard of this requirement (but not an elastic user so no surprise).