Why does PostgreSQL perform sequential scan on indexed column?
Very simple example – one table, one index, one query: CREATE TABLE book ( id bigserial NOT NULL, “year” integer, — other columns… ); CREATE INDEX book_year_idx ON book (year) EXPLAIN SELECT * FROM book b WHERE b.year > 2009 gives me: Seq Scan on book b (cost=0.00..25663.80 rows=105425 width=622) Filter: (year > 2009) Why … Read more
