Tom Lane escribió: > Alvaro Herrera <[EMAIL PROTECTED]> writes: > > Tom Lane escribió: > >> It would only be useful to have one per spindle-dedicated-to-WAL, so > >> tying the division to databases doesn't seem like it'd be a good idea. > > > Keep in mind that there are claims that a write-cache-enabled > > battery-backed RAID controller negates the effect of a separate spindle. > > Possibly true, but if that's the underlying hardware then there's no > performance benefit in breaking WAL up at all, no?
Selective PITR shipping. > > My point, rather, is that with this sort of setup it would be easier to > > do per-database PITR shipping, and one database's WAL activity would not > > affect another's (thus hosting providers are happier -- high-rate > > customer A need not affect low-budget customer B). > > You won't get far with that because of the shared catalogs. In > particular, most DDL operations these days touch pg_shdepend ... That's why you log shared activity to another WAL stream, and ship that to everyone, while the other databases' WAL streams are shipped only to the interested slaves. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
