Aren Cambre <aren(at)arencambre(dot)com> writes:
> Just want to again emphasize that my database state has changed, so I am
> not sure this is remains a good case for finding a bug.
Your description of an apparently-all-nulls row sounds a great deal like
data corruption. I suspect there may be more wrong than just the one
row, and that that's what's leading to the inconsistent results. It'd
be worthwhile to run hardware diagnostics (memtest, disk tests), make
sure you are on the latest minor release of Postgres, and perhaps do a
database dump and reload. (If the latter seems impractical, at least
consider reindexing everything.)
regards, tom lane