Hello. I did the POC (1) of the method described in the previous email, and it looks promising.
It doesn't block the VACUUM, indexes are built about 30% faster (22 mins vs 15 mins). Additional index is lightweight and does not produce any WAL. I'll continue the more stress testing for a while. Also, I need to restructure the commits (my path was no direct) into some meaningful and reviewable patches. [1] https://github.com/postgres/postgres/compare/master...michail-nikolaev:postgres:new_index_concurrently_approach
