Traditional indexes suffer because they must write to a log before they write to the disk. The introduces Speculative Execution . It assumes the transaction will succeed and caches the result in a volatile memory ring before validation. If the transaction fails, the index rolls back so fast that the latency is imperceptible to the user.
CREATE INDEX CONCURRENTLY idx_superbad_new ON your_table USING superbad (column_name); superbad index new