Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> writes:
> On Wed, Sep 20, 2017 at 4:25 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Yes. We don't allow out-of-line values, but we do allow compressed and
>> short-header values.
> BTW, this comment looks still invalid for me...
>> #define SIGLENINT 4 /* >122 => key will *toast*, so very slow!!! */
I haven't done the math to see if 122 is exactly the right value,
but at some point index_form_tuple would decide that the tuple was
uncomfortably big and try to compress it. So the comment is right
in general terms.
regards, tom lane