Shulou(Shulou.com)05/31 Report--

This article mainly introduces "the writing method of paging in oracle". In the daily operation, I believe that many people have doubts about the writing method of paging in oracle. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts of "paging writing in oracle". Next, please follow the editor to study!

I. efficient writing

1. There is no way to write ORDER BY sort. (most efficient)

After testing, this method has the lowest cost, only one layer is nested, and the speed is the fastest! No matter how large the amount of data queried, it is almost unaffected, and the speed is still the same!)

SELECT * FROM (SELECT ROWNUM AS rowno, t.* FROM emp t WHERE hire_date BETWEEN TO_DATE ('20060501,' yyyymmdd') AND TO_DATE ('20060731),' yyyymmdd') AND ROWNUM = 10

two。 There is an ORDER BY sort of writing. (more efficient)

After testing, with the expansion of the query scope, the speed of this method will become slower and slower!

SELECT * FROM (SELECT tt.*, ROWNUM AS rowno FROM (SELECT t.* FROM emp t WHERE hire_date BETWEEN TO_DATE ('20060501,' yyyymmdd') AND TO_DATE ('20060731,' yyyymmdd') ORDER BY create_time DESC, emp_no) tt WHERE ROWNUM = 10 1234567891011121314151617 at this point, the study of "paging writing in oracle" is over. I hope I can solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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