thank you Cetin
And what is the right tool for you ?
for me i tested the vfp project i shipped and it works , no exactly as everything but its a good start: http://yousfi.over-blog.com/2018/05/instantaneous-search-filer-with-vfp.html
-the windows scheduler updates in background one table of all files as well (~10 mn).its a big table comparatively to everything.db but must introduce some accelerators as you said (to reduce the table size significatively and make access just in time without rebuilding it all times).And this is vfp database developer speciality.
-the searcher is basic but makes good work and search is performent.
all these are basic and can be performed.infortunatly i have any feed back..

we speak on vfp language and want vfp to solve this problem with the effort of communauty even if its stopped there is more 10 ans.
i wanted vfp starting with a filer like this instead of the filer (based on filer.dll) shipped with vfp versions and full of problems..
in old vfp time any important subject created mobilizes the efforts of all developers....today they all seem discouraged...
in any other cases, i like "everything" tool and i tried its command lines exclusively with vfp.the tests are satisfactory.

in my point of view,its a necessary work even if for others they dont want to be.At least the problem is pointed.