SME's have been suggesting from 7.16 that it's not required to delete extract marker. If you used to use the extract marker file to clear the static content file-based cache, to look up lists, or to control starting activities with web nodes, you can delete the contents of the PegaRULES temporary directory instead.
For 7.2.1 and later versions, to clear the cache you should delete the contents of the PegaTemp folder. This will do the same as deleting the extract marker in earlier versions.
There is some caching in the database, but you should not do a database cache clear unless you've been instructed to do so by Pega. It's almost never needed in Pega 7 (unlike some earlier versions of Pega). If it comes up, Pega will provide a query to do so.
You can ignore this question. I found the answer thanks to Nick L. As of today, only 7.2.1 does not use an extract marker. Due to RUF architecture changes it was removed in that release. But it was quickly added back in 7.2.2.