Match financial transactions and merchants

[fabiobozzo]

I have an Elastic index with billions of transactions.

An example tx:

{
   "id": "54bfa9af-009a-437d-bd21-caaf651f7218",
   "amount": 100.0, 
   "currency": "EUR",
   "type": "expense",
   ...
   "note": "CARD PAYMENT TO AZAMON.COM 100.0 EUR, RATE 0.86/GBP ON 05-05-2022"
}

I have a few millions merchants (companies, etc.) in a RDBMS table:

id    | Name
123   | Azamon Ltd
456   | Alple Inc.
789   | Goooogle
...

I can easily ingest them in another Elastic index.

Now, both transaction's note and merchant's name are analyzed fields.

I would like, for every new transaction indexed, to enrich its content with a merchant ID+name. It doesn't have to be perfect, though. A threshold score could be fine tuned once the solution works for most of the matching tx.

e.g.

for the tx above, I would like to obtain "123, Azamon Ltd" as a search result

Should I just create a custom tokenizer, analyzer for that, and run a query against a "merchants" index using the tx note as a search term? What would be a good pipeline structure for single-language tx/merchants matching?

Or is there a out-of-the box more efficient solution for that problem? I'm reading about NER, documents similarity and other stuff, but I can't figure out what's the best approach in my (simple) case.

Pointing me to relevant and proven doc pages will be considered an acceptable answer. TY