I could believe it — I’m pretty sure I’ve done it before using Postgres. Benchmarks appear to confirm this possibility —- 100 million towns indexed in about 35 mins using the standard b tree index, and 20 mins for BRIN on a laptop in 2019: https://blog.crunchydata.com/blog/postgresql-brin-indexes-bi...
Elasticsearch is famous for slow indexing. This is basically because it is trading off slow indexing for fast search later.
And data to be indexed was incredibly complex and rich. So every detail of every car you own, family member information, addresses, phone numbers, emails, identification documents, details of your contracts, and so on.
