Oracle Sequencing issues

Table test Data

SELECT * FROM Test ORDER BY name Desc

Results:

1-1:select * FROM (select A.*,rownum rn from Test A order by name ASC) where RN between 0 and 10

Results:

1-2:select * FROM (select A.*,rownum rn from Test A ORDER by name Desc) where RN between 0 and 10

Results:

2-1:select a.*,rownum from Test A where rownum between 0 and ten order by name Desc

Results:

2-2:select a.*,rownum from Test A where rownum between 0 and ten order by name ASC

Results:

3-1:select * FROM (select A.*,row_number () up (order by name Desc) as RN from Test A) where RN between 0 and 10

Results:

3-2:select * FROM (select A.*,row_number () over (order by name ASC) as RN from Test A) where RN between 0 and 10

Results:

Conclusion: The third type of query is to sort and fetch data first, and the first two is to fetch the data after the query, for the field is not the primary key.

Oracle Sequencing issues