Re: MultiXactId error after upgrade to 9.3.4

>>>>> "Alvaro" == Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> writes:

>> (It can, AFAICT, be inside the currently valid range due to
>> wraparound, i.e. without there being a valid pg_multixact entry for
>> it, because AFAICT in 9.2, once the mxid is hinted dead it is never
>> again either looked up or cleared, so it can sit in the tuple xmax
>> forever, even through multiple wraparounds.)

Alvaro> HeapTupleSatisfiesVacuum removes very old multixacts

It does nothing of the kind; it only marks them HEAP_XMAX_INVALID. The
actual mxid remains in the tuple xmax field.

The failing mxids in the case I analyzed on -bugs are failing _in spite
of_ being already hinted HEAP_XMAX_INVALID, because the code path in
question doesn't check that.

--
Andrew (irc:RhodiumToad)