Re: Buglist

>>>>> "AH" == Alvaro Herrera <alvherre@dcc.uchile.cl> writes:

>> once within a vacuum process.  I am fairly certian it would reduce
>> disk bandwidth requirements since at least one necessary page will
>> already be in memory.

AH> There's no way to check for "external references", because said
AH> references are actually the running transactions.  So you can't drop a
AH> row until all the transactions that were active during your transaction

How does the backend running vacuum detect that a row has no active
references?  Why can't the current backend know that same information?