How do I limit the number of rows returned by an Oracle query after ordering?

Question

Is there a way to make an Oracle query behave like it contains a MySQL limit clause?

In MySQL, I can do this:

Answer 1

I did some performance testing for the following approaches:

Asktom

select * from (
  select a.*, ROWNUM rnum from (
    
  ) a where rownum <= MAX_ROW
) where rnum >= MIN_ROW


Analytical

select * from (
  
) where myrow between MIN_ROW and MAX_ROW

Short Alternative

select * from (
  select statement, rownum as RN with order by clause
) where a.rn >= MIN_ROW and a.rn <= MAX_ROW

Results

Table had 10 million records, sort was on an unindexed datetime row:

• Explain plan showed same value for all three selects (323168)
• But the winner is AskTom (with analytic following close behind)

Selecting first 10 rows took:

• AskTom: 28-30 seconds
• Analytical: 33-37 seconds
• Short alternative: 110-140 seconds

Selecting rows between 100,000 and 100,010:

• AskTom: 60 seconds
• Analytical: 100 seconds

Selecting rows between 9,000,000 and 9,000,010:

• AskTom: 130 seconds
• Analytical: 150 seconds