>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.
Now i got the point. Initially, i thought for n keys to extract from json only one time the full json is decompressed. But it's actually decompressing n times for n keys.