this post was submitted on 15 Dec 2023
8 points (83.3% liked)

Programming

17540 readers
68 users here now

Welcome to the main community in programming.dev! Feel free to post anything relating to programming here!

Cross posting is strongly encouraged in the instance. If you feel your post or another person's post makes sense in another community cross post into it.

Hope you enjoy the instance!

Rules

Rules

  • Follow the programming.dev instance rules
  • Keep content related to programming in some way
  • If you're posting long videos try to add in some form of tldr for those who don't want to watch videos

Wormhole

Follow the wormhole through a path of communities [email protected]



founded 2 years ago
MODERATORS
 

If you are wondering why lemmy is moving away from offset pagination since 0.19, here is a nice article about it

all 9 comments
sorted by: hot top controversial new old
[–] [email protected] 4 points 11 months ago (2 children)

For the article-impaired,

Using OFFSET+LIMIT for pagination forces a full table scan, which in large databases is expensive.

The alternative proposed is a cursor+based navigation, which is ID+LIMIT and requires ID to be an orderable type with monotonically increasing value.

[–] [email protected] 2 points 11 months ago

Which it almost never is.

Any data as simple as that is unlikely to reach a number of rows likely to cause an issue with performance.

[–] [email protected] 1 points 11 months ago* (last edited 11 months ago)

Having said this, I'd say that OFFSET+LIMIT should never be used, not because of performance concerns, but because it is fundamentally broken.

If you have rows being posted frequently into a table and you try to go through them with OFFSET+LIMIT pagination, the output from a pagination will not correspond to the table's contents. Fo each row that is appended to the table, your next pagination will include a repeated element from the tail of the previous pagination request.

Things get even messier once you try to page back your history, as now both the tip and the tail of each page will be messed up.

Cursor+based navigation ensures these conflicts do not happen, and also has the nice trait of being easily cacheable.

[–] YodaDaCoda 2 points 11 months ago (1 children)

Is there a way I can access this article without making an account?

I'm not going to make an account.

[–] [email protected] 4 points 11 months ago (1 children)

Sorry for inconvenience, I updated the link

[–] YodaDaCoda 2 points 11 months ago

Oh thanks mate 👍

Interesting article but I kinda fail to see how you'd go if your paginating through sorted rows - you'd have to have an id in the sequence of your sort order?

[–] hostops 1 points 11 months ago (1 children)

Still wants me to make an account.

[–] [email protected] 2 points 11 months ago* (last edited 11 months ago)

That's really weird, because I have no account on medium and it works for me. Maybe try this link instead:

https://ivopereira.net/efficient-pagination-dont-use-offset-limit