利用延迟关联或者子查询优化超多分页场景

EXPLAIN SELECT * FROM `demo` limit 300000,20
EXPLAIN SELECT a.* FROM demo a, (select id from demo LIMIT 300000,20 ) b where a.id=b.id
EXPLAIN SELECT * FROM `demo` limit 300000,20
EXPLAIN SELECT a.* FROM demo a, (select id from demo LIMIT 300000,20 ) b where a.id=b.id