[snip]
> IMHO *most* UPDATEs occur on non-indexed fields. [snip]
>
> If my assumption is badly wrong on that then perhaps HOT would not be
> useful after all. If we find that the majority of UPDATEs meet the HOT
> pre-conditions, then I would continue to advocate it.
Just to confirm that the scenario is valid: our application has almost
all it's updates affecting only non-indexed columns. There are a few
exceptions, but the vast majority is non-indexed, and that holds to the
execution frequency too, not just for the count of tables/queries.
Cheers,
Csaba.