Rendering of Files Speed Versus Rendering from Databases

I came across a blog entry about how session stores are much faster
when using a database versus flat files (pstore). And I must say that
even with SQLite I notice a huge difference after switching.

What I was wondering is if people have found rendering .liquid
templates out from the database is actually faster than from a file on
the filesystem.

And if this is the case, what is the cause of the slowdown? It seems a
bit odd that reading a text file would cause so much extra rendering
time. Is this a Ruby issue or a Rails?

-Paul