Re: HeapTupleSatisfiesToast() busted? (was atomic pin/unpin causing errors) - Mailing list pgsql-hackers

From Tom Lane
Subject Re: HeapTupleSatisfiesToast() busted? (was atomic pin/unpin causing errors)
Date
Msg-id 2491.1462889347@sss.pgh.pa.us
Whole thread Raw
In response to Re: HeapTupleSatisfiesToast() busted? (was atomic pin/unpin causing errors)  (Andres Freund <andres@anarazel.de>)
Responses Re: HeapTupleSatisfiesToast() busted? (was atomic pin/unpin causing errors)  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
Andres Freund <andres@anarazel.de> writes:
> Is anybody ready with a good defense for SatisfiesToast not doing any
> actual liveliness checks?

As long as we do not update toast values after creation, there is no
need; the liveness check on the parent tuple is what's important.
Adding a liveness check on the toast item would merely create new
failure modes with no corresponding benefit.  Imagine deciding
that field 3 of a regular tuple was somehow dead even though the
rest of the tuple is live --- how can that be good?

I concur with Robert that what this looks like is failure to ensure
that toast OIDs are unique, which is an entirely different problem.
        regards, tom lane



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