Heikki Linnakangas <hlinnakangas@vmware.com> writes:
> On 09/24/2014 08:16 AM, Tom Lane wrote:
>> Heikki's patch would eat up the high-order JEntry bits, but the other
>> points remain.
> If we don't need to be backwards-compatible with the 9.4beta on-disk
> format, we don't necessarily need to eat the high-order JEntry bit. You
> can just assume that that every nth element is stored as an offset, and
> the rest as lengths. Although it would be nice to have the flag for it
> explicitly.
If we go with this approach, I think that we *should* eat the high bit
for it. The main reason I want to do that is that it avoids having to
engrave the value of N on stone tablets. I think that we should use
a pretty large value of N --- maybe 32 or so --- and having the freedom
to change it later based on experience seems like a good thing.
regards, tom lane