"Tom Lane" <tgl@sss.pgh.pa.us> writes:
> Jeff Davis <pgsql@j-davis.com> writes:
>> On Sun, 2008-01-13 at 18:52 -0500, Tom Lane wrote:
>>> I wonder whether there are any other places that are silently assuming
>>> that heapscans start from page zero ...
>
>> I considered that question when implementing sync scans, but I could not
>> think of any specific areas of the code that would likely be affected.
>
> I went through all of the heap_beginscan calls in the code last night.
> pgstattuple was broken but AFAICS none of the other callers care about
> the visitation order. I wonder though about third-party add-ons :-(
Perhaps we ought to have made heap_beginscan guarantee an ordered scan and
made synch scans be explicitly requested. That would have touched a lot of
lines but been more conservative. I'm not sure it's worth going back on it now
though.
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