"Jack Orenstein" <jack.orenstein@gmail.com> writes:
> I understand that updating a row of t generates a new row version, and
> that different transactions may see different versions of the same
> row.
> How does versioning work for the index?
Each row version has its own index entry pointing to it. So an update
is not a lot different from an insert --- they both generate a full set
of index entries.
regards, tom lane