I have a number of dash apps I am running which generally fall into one of two categories, displaying datatables or displaying plots. I have noticed that for those which display plots, any of the callbacks which produce the plots run extremely slowly the first time they are run, whereas after that they run almost instantly which is what I would expect from them. For example I have used the callback graph to look at how long they are taking and in one case I find that on the first run it takes 8 seconds for each callback to run but after this the average runtime will work down to the order of milliseconds if it is rerun many times through changing, removing, replotting the graph by adjusting input parameters. Is this known/expected behaviour? I can not find any information here on this? These graphs are plotly figures id dcc.Graph components btw. I do not see the same behaviour on apps which only produce datatables.
Did you find an answer to this? Iām having the same issue with plotly express, first run is super slow, and subsequent runs (even with different data), are almost instant.
Is the initial run just the one that is loading the dataframe from your source? After that is it just callbacks that are manipulating or reusing the data held in the dataframe?
I havenāt had that problem myself, even with chained callbacks updating 4 graphs, but my project is running on my local machine. Maybe in production and/or under heavier load it would appear.