Tom Lane wrote: > Bruce Momjian <[EMAIL PROTECTED]> writes: > > Gregory Stark wrote: > >> I have a question about what would happen for a transaction running a > >> command > >> like COPY FROM. Is it possible it would manage to arrange to have no live > >> snapshots at all? So it would have no impact on concurrent VACUUMs? What > >> about > >> something running a large pg_restore? > > > Interesting idea. > > Indeed. Currently, COPY forcibly sets a snapshot on the off chance > something will use it, but I could certainly see making that happen > "lazily", ie not at all in the simple case. > > pg_restore is probably a lost cause, at least if you are running it > in single-transaction mode. I guess there'd be tradeoffs as to whether > to do that or not ...
The bottom line is that more optimizations for VACUUM dead tuple identification are possible. -- Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
