Re: Duplicate values found when reindexing unique index

Gregory Stark <stark@enterprisedb.com> writes:
> "Tom Lane" <tgl@sss.pgh.pa.us> writes:
>> I wonder whether it's just a coincidence that these have the same offset
>> number...

> I can't imagine any Postgres bug which would depend on the offsets
> being the same. But what I could imagine is filesystem corruption
> which copied the block to someplace else in the table or possibly has
> even mapped the same block into two different places in the table.

That idea was in my mind too, but Mason stated that the rows showed
different "updated_at" values, so they couldn't be mirror images of that
sort.  The pg_filedump output for the two blocks would be more conclusive
about this though --- I was expecting to pay attention to the whole
block contents not only the seemingly-dup rows.

            regards, tom lane