MySQL in and limit performance

HI: A performance questions: In MySQL, when display a list, I have two stratergy to display it:
SQL One:
select * from tablename where id in (some arrays);  

SQL Two:

select * from tablename limit 10,10;

Questions: Which query is faster?

In query one: If array size is 20 and 100, does it mean 100 is 5 times slower than 20.
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

theGhost_k8Database ConsultantCommented:
Use explain to check query performances.
"in" should use indexes to perform quicker.
"limit n,m" will require full table scan which we try to avoid normally.

The difference wont be that large.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
theGhost_k8Database ConsultantCommented:
Mean while about pagination have a look at this:
The second one is probably faster as written, but usually if you have LIMIT you also have ORDER BY, and then it's probably slower. Depends on if there are indexes involved and how big the table is.

It's hard to say exactly how different looking up 20 values vs. 100 values would be; the easiest thing would be to just try it and see.
Newly released Acronis True Image 2019

In announcing the release of the 15th Anniversary Edition of Acronis True Image 2019, the company revealed that its artificial intelligence-based anti-ransomware technology – stopped more than 200,000 ransomware attacks on 150,000 customers last year.

JianJunShenAuthor Commented:
Hi theGhost_k8:

What about I have less than 10,000 records. Does that worthe indexing in order for faster speed? Or in other way, if my table rows are less than 10,000, use in or use limit?
theGhost_k8Database ConsultantCommented:
Have you checked actually executing queries?
I see limit n,m easily manageable - considering there'd be less performance differences.
In case of "order by", you check the difference in both the queries.
Make sure, you keep the query_cache off / use SQL_NO_CACHE for comparison.
JianJunShenAuthor Commented:
Hi:  experts:

Do you have some links to tell how to check the SQL performance? How faster it is and how many memory it consumes?
theGhost_k8Database ConsultantCommented:
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
MySQL Server

From novice to tech pro — start learning today.