Alvaro Herrera <[EMAIL PROTECTED]> writes:
> Tom Lane wrote:
>> But the patch changes things so that *everyone* excludes the vacuum from
>> their xmin.  Or at least I thought that was the plan.

> We shouldn't do that, because that Xmin is also used to truncate
> SUBTRANS.

Yeah, but you were going to change that, no?  Truncating SUBTRANS will
need to include the vacuum xact's xmin, but we don't need it for any
other purpose.

> but it means
> lazy vacuum will never be able to use subtransactions.

This patch already depends on the assumption that lazy vacuum will never
do any transactional updates, so I don't see what it would need
subtransactions for.

                        regards, tom lane

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