Mark Dilger <mark.dil...@enterprisedb.com> writes:
>> On Oct 22, 2020, at 2:06 PM, Tom Lane <t...@sss.pgh.pa.us> wrote:
>> Oh, wait a second. ItemIdData has the flag bits in the middle:
>> meaning that for that particular bit pattern, one endianness
>> is going to see the flags as 01 (LP_NORMAL) and the other as 10
>> (LP_REDIRECT).
> Well, the issue is that on big-endian machines it is not reporting any
> corruption at all. Are you sure the difference will be LP_NORMAL vs
> LP_REDIRECT?
[ thinks a bit harder... ] Probably not. The byte/bit string looks
the same either way, given that it's four repetitions of the same
byte value. But which field is which will differ: we have either
oooooooooooooooFFlllllllllllllll
01110111011101110111011101110111
or
lllllllllllllllFFooooooooooooooo
01110111011101110111011101110111
So now I think this is a REDIRECT on either architecture, but the
offset and length fields have different values, causing the redirect
pointer to point to different places. Maybe it happens to point
at a DEAD tuple in the big-endian case.
regards, tom lane
