Re: jsonb format is pessimal for toast compression

Josh Berkus <josh@agliodbs.com> writes:
> And with Tom's test patch:
> ...
> Since that improved things a *lot*, just +40% instead of +200%, I
> thought I'd test some select queries.

That test patch is not meant to be fast, its ambition was only to see
what the effects on storage size would be.  So I find this unsurprising:

> ... so, an 80% increase in lookup and extraction time for swapping
> offsets for lengths.

We can certainly reduce that.  The question was whether it would be
worth the effort to try.  At this point, with three different test
data sets having shown clear space savings, I think it is worth
the effort.  I'll poke into it tomorrow or over the weekend, unless
somebody beats me to it.
        regards, tom lane