Tom Lane wrote: > Alvaro Herrera <[EMAIL PROTECTED]> writes: > > Tom Lane wrote: > >> nonInVacuumXmin seems useless ... perhaps a vestige of some earlier > >> version of the computation? > > > Hmm, not useless at all really -- only a bug of mine. Turns out the > > notInVacuumXmin stuff is essential, so I put it back. > > Uh, why?
Because it's used to determine the Xmin that our vacuum will use. If there is a transaction whose Xmin calculation included the Xid of a transaction running vacuum, we have gained nothing from directly excluding said vacuum's Xid, because it will affect us anyway indirectly via that transaction's Xmin. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
