Jim Nasby <Jim(dot)Nasby(at)BlueTreble(dot)com> writes:
> I never dug into why. As Tom posited, decompression might explain the
> time to get a single key out. Getting 10 keys instead of just 1 wasn't
> 10x more expensive, but it was significantly more expensive than just
> getting a single key.
What were you doing to "get ten keys out"? If those were ten separate
JSON operators, they'd likely have done ten separate decompressions.
You'd have saved something by having the TOAST data already fetched into
shared buffers, but it'd still hardly be free.
regards, tom lane