Hi,
The memory on your machine has a big influence on your Alteryx performance, so first of all, if you're going to treat a larger set of data, or doing a lot of in memory sorting, working a lot with Alteryx, consider putting in some extra memory in your machine. 16GB is nice, 32GB better - things just run a whole lot faster then for a very small price (if IT agrees).
I think the default settings are to take 25% of what is available - just not to lock up all your other applications.
The rest if it overruns it writes out to your Alteryx Temp drive (which can run out the space on your C drive at times - in which case set it to elsewhere). So when there is too much ... it swaps in and out. - you can see it somewhere under your local app ... (Can be changed in system settings I think) Then on workflow level you can override this Global Level - Under Runtime on the left of your canvas - Set to use a specific amount (but if you go there, it allocates this block of memory by default all the time during that workflow)...and Alteryx tends to mention, don't go there unless you know what you're doing ;) Could give it a try allocating there.
Could it be that you have your specific amount on the workflow or in the global default set too high for what's left? - Was it perhaps for this flow set on a higher grade machine and your now running it on a lower spec. Then you might want to try : Set it back to Global Default perhaps?
... a few thoughts only, I'm not a memory expert.
