The Same Row Twice: Four Things Keyset Pagination Needs

Speed is OFFSET's second problem. The first is that page 2 can hand you a row you already read on page 1 — and no index will fix it, because it is not a performance bug. Part 1 of this series measured why deep OFFSET is O(depth): at depth 9,999,980 PostgreSQL reads ten million rows and discards all but twenty. This is the other half — why you...