Switching tabs incredibly slow

[kirk77]

Thank you. In my case I cannot store the data in the backend. storing in hidden div is my best option as i see that even dcc store also has space limitations.

[fohrloop]

In addition to a hidden div (user’s browser memory) you can store data into the server’s memory (not hard disk) using the Flask-Caching with Redis (link in above comment). This might help in situations where there is lot of data (too much for browser memory). But in your case, you would need to get the dcc.Upload contents to be emptied somehow. Unfortunately I don’t know how to do that programmatically (of course it’s possible to make it almost empty by uploading empty dummy file manually).

[chriddyp]

@chriddyp

Thanks for reporting! We’ve noticed something similar - Currently the dash code crawls through all of the rendered components on the page to see if it needs to display a loading component whenever an update changes. So, if you have 1000 components on the page (which is very easy to achieve if you are using html.Table because each cell is a component), the it’ll crawl through 1000 items and perform some checks on each item. Most of the time it’s unnoticeable, but in certain apps it can feel pretty slow.
We’re reworking this part of the code right now in https://github.com/plotly/dash/pull/1254 . It will be available in the next release and we’d love your feedback once it’s out!

This is now out in 1.13.0, you can try upgrading with:

pip install dash --upgrade

@chriddyp

@chriddyp

Could you share a simple, reproducible example that demonstrates the performance issues?

This request still stands! We can only fix issues that we can reproduce, so if anyone can create an example with synthetic or mock data (eg it could be the same string in every element) that mimics the structure and number of components in your app, that’s be much appreciated.

This request still stands