Hello: Thank you all.
I have understood this. Best Regards 2013/8/31 Kevin Grittner <kgri...@ymail.com> > 高健 <luckyjack...@gmail.com> wrote: > > > So I think that in a mission critical environment, it is not a > > good choice to turn full_page_writes on. > > If full_page_writes is off, your database can be corrupted in the > event of a crash of the hardware, OS, or VM (for example a power > failure). The only exception is if your environment somehow > guarantees that in such failures it is not possible to write part > of a 4KB write request without the entire 4KB being written. Such > corruption may be hidden and result in inconsistent or incorrect > results, without generating an error; so you would be well-advised > to restore from backup if there is such a crash. > > full_page_writes = on is required for protection of database > integrity in most environments. > > In the mission critical environments I've worked with, it has > generally been desirable to preserve database integrity and to be > able to recover from an OS crash faster than can be done from > backup. > > -- > Kevin Grittner > EDB: http://www.enterprisedb.com > The Enterprise PostgreSQL Company >
