I'm working on a geometry nodes setup, there is one node which input doesn't change, but this node takes a long time to calculate, and I'm constantly changing things that aren't affecting this node, is there a way I can skip its calculations? Kinda like the freeze icon in Houdini. I guess the answer is no, since I couldn't find anything, but maybe someone knows something cool.
This answer is for Blender versions lower than 3.6, if you are using 3.6+ you can find the solution in the other answer.
No, unfortunately this is definitely not possible in Blender with Geometry Nodes.
...even if I would like to have exactly this possibility as much as you!
Either the nodes are active and create a geometry, or they are not.
A temporary caching of a certain part of a node tree, as it is possible for example in Houdini, is unfortunately not achievable in Blender.
The only alternative you would have would be:
Create the computationally expensive part as a separate node tree, and create a permanent geometry from it each time by applying the modifier. However, this process would then have to be performed again after each modification.
It is no longer true that Blender cannot cache the result of a node in Geometry Nodes.
From Blender 3.6 and onwards, Blender Foundation have added the Simulation Zone nodes to Blender, which can encapsulate a portion of your nodes.
Once you have successfully encapsulated the nodes you wish to cache, move over to the Physics tab within the Properties editor and find the Simulation Nodes section. Note that while this was placed in the physics section, it will cache anything that comes out of the zone, not just physics.
If it is not expanded, expand it. Now you can select the Cache checkbox, and then choose either the Calculate to frame or Bake options to cache the data which you need.
Once this is enabled, you need to delete the data with the little trash can button next to bake to remove the data or click bake again (or both) when you do something that might update the results of the nodes within the simulation zone.
Also note that for versions 4.0+ Blender has another zone type called Repeat Zone, which is distinct, and at the time of writing this does not allow caching for that zone type (unless perhaps if encapsulated in a simulation zone, but I have not tested this to see if it works).
I am hopeful that they will add some smarter built-in caching and detection of which changes in data flow would require updating of caches automatically, but Simulation Zones are what we have for now.