Thanks !! I'm not using any experimental OS :) CentOS it is :) But, from https://www.sqlite.org/tempfiles.html it's not clear all temp files and transient indices files names convention, it's clear for WAL, Journals and so. But for other it's not that clear, and possible can cause interference between temp files if they're having same names. So this I wanted to avoid. Nothing special or exeperimental. Slava