On Wednesday 21 February 2007 01:43, Amos Shapira wrote: > On 20/02/07, Tzahi Fadida <[EMAIL PROTECTED]> wrote: > > In PostgreSQL they don't even do the caching (more or less), they let the > > OS > > to do it. This is a common question and the claim of the PostgreSQL dev > > community is that the added benefit of a raw fs will be negligable. I for > > one > > believe it because many of them uses oracle also. Not to mention > > PostgreSQL > > is more or less compatible in syntax with oracle. I also can tell you > > that with recent stable versions 8+ and recent kernels you can probably > > achieve almost raw fs capabilities by using certain file options (which > > they do). They also use techniques as back writings etc... This thing is > > very advanced. > > Thanks for the clarification. > > > That (battey-backed RAM) sounds like a good tip. Will keep it around. > > > > > Thanks. If you have more specific details to help Google for such a > > > > product > > > > > I'll appreciate to hear them. > > > > Check out these sites, i think these are the real thing: > > http://www.anandtech.com/tradeshows/showdoc.aspx?i=2431&p=5 > > http://www.cenatek.com/ > > > > However, also remember to periodically back up your stuff to the HD. I > > trust > > batteries only so far. :) > > Well - if I use it only for transaction logging then hopefully the data > there will be useful only for fractions of seconds, wouldn't it?
Depends. Sometimes queries takes longer. However it is not the point. The reason for backupping once in a while is for PITR - point in time recovery which is a new facility in PostgreSQL 8+. I am not an expert on this subject but IIRC, imagine you backupped the database at 8am. At 9am the database crashed. The data at the database is too corrupt due to various insane reasons you can conjure in your mind. However, the transaction log survived. It turns out, it kept all the transactions back to 8am when you backed up your database. YAY!, you can basically rerun all the transactions from that time using the log and reconstruct the database. > > Thanks, > > --Amos -- Regards, Tzahi. -- Tzahi Fadida Blog: http://tzahi.blogsite.org | Home Site: http://tzahi.webhop.info WARNING TO SPAMMERS: see at http://members.lycos.co.uk/my2nis/spamwarning.html ================================================================To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
