Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
> Denis <denis(dot)sailer(at)yellowbook(dot)com> writes:
>> There were 1905028 unused item pointers.
> The "unused item pointers" number seems a bit high, but otherwise that
> looks pretty reasonable.
>
> Is it possible that the particular row you were updating has been
> updated quite a lot of times since the last vacuum? Or even quite
> a few times within a single transaction?
What causes this "unused item pointers" and which impact do they have
regarding performance?
If I understood your last posting correctly more than one update on a
single row between two vacuum's would i.e. result in one ore more
"unused item pointer". Does this slow down the vacuum process and/or
other processes? Until now I could not find an answer what this number
implies.
Regards
Martin