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
The amount of disk input-output	> 2x	2x
The amount of required disk space	limited by WAL settings	2x
Data overhead	yes^{(1-2 bytes per page)}	no
performancePerformance^{(rough estimate)}	slower	faster
Implementation complexity ^{(rough estimate)}
stable Stable topology, read-only	simple	simple
online Online updates	simple	complex
unstable Unstable topology	simple	complex

Copy with re-encryption design.

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