Oracle三种分页方式及效率对比
insert into student select * from student;select ROWNUM,t.* from student t where rownum <5;select count(*) from student;--786432条，--查 78000～78030 速度由快到慢：1-2-3-4--1.按rownum 来分select * --0.094S from (select rownum as rn , st.* from (select * from student) st where rownum <78030) t where rn > 78000;--2.按rownum 来分select * --0.343S from (select rownum as rn, st.* from (select * from student) st) where rn between 78000 and 78030;--3 按rowid来分 select * --0.359S from student where rowid in (select rid from (select rownum rn, rid from (select rowid rid, classid from student order by classid) where rownum < 78030) where rn > 78000) order by classid; --4 按分析函数来分select * -- 0.624S from (select t.*, row_number() over(order by classid) rk from student t) where rk < 78030 and rk > 78000;
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