Process photoanalysisd takes huge amount of memory

The "photoanalysisd" process in my mid 2011 iMac running macOS 10.13.6 takes an enormous amount of memory space (about 60 GB), causing a very large use of swap (about 20 GB), as you can see in the screenshot. This has been going on for several months (I never turn off my iMac). My iMac is not responding. In order to use it, I must first kill the process. And kill it again after a few minutes, again and again.

I know that photoanalysisd takes a lot of CPU time, but why does it also take so much memory continuously?

Thank you