I'm trying to apply the 'join attributes by nearest' function on a quite big dataset: A multipolygon layer with ~ 415.000 features (1.11GB) and a point layer with ~ 305.000 features (~320 MB). Just to give you an idea on the data, I have added a small snippet of how the data looks like.
As can be seen the polygon layer is pretty complex, and I think, this is the problem.
I tried the 'join attributes by nearest' on a small clip of the data, and it works like a charm and gives exactly the output I need. However, when I run it with the whole data set, the first 50% are pretty fast (it takes a couple of seconds to reach up to 50%), and then it gets more or less stuck and afterwards takes ~ 1h per 1%.
I know this is a broad question, however, if someone has experience how to accelerate the processing of this function (join attributes by nearest) I would be very glad to hear about! I'm of course also open for other methods to use for this kind of problem.
I hope this question doesn't get closed as I understand, that it is relatively broad. I just hoped, there would be someone who had to solve a similar problem with the same function already, too.
QGIS 3.28 Firenze