This strategy requires changing the format of the encryption page to store the identifier (number) of the encryption key.

Comparison

	in place	copy
IO volume	2+	2
overhead	yes^{(1-2 bytes per page)}	no
performance^{(rough estimate)}	slower	faster
Implementation complexity ^{(rough estimate)}
stable topology, read-only	simple	simple
online updates	simple	complex
unstable topology

changes

simple

complex

Copy with re-encryption design.

...