On Fri, 18 Feb 2005 04:38 pm, Kevin Brown wrote: > Tom Lane wrote: > > Gaetano Mendola <[EMAIL PROTECTED]> writes: > > > BTW, why not do an automatic vacuum instead of shutdown ? At least the > > > DB do not stop working untill someone study what the problem is and > > > how solve it. > > > > No, the entire point of this discussion is to whup the DBA upside the > > head with a big enough cluestick to get him to install autovacuum. > > > > Once autovacuum is default, it won't matter anymore. > > I have a concern about this that I hope is just based on some > misunderstanding on my part. > > My concern is: suppose that a database is modified extremely > infrequently? So infrequently, in fact, that over a billion read > transactions occur before the next write transaction. Once that write > transaction occurs, you're hosed, right? Autovacuum won't catch this > because it takes action based on the write activity that occurs in the > tables. > > So: will autovacuum be coded to explicitly look for transaction > wraparound, or to automatically vacuum every N number of transactions > (e.g., 500 million)? > autovacuum already checks for both Transaction wraparound, and table updates. It vacuums individual tables as they need it, from a free space/recovery point of view.
It also does checks to ensure that no database is nearing transaction wraparound, if it is, it initiates a database wide vacuum to resolve that issue. Regards Russell Smith > > ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])