Обсуждение: Postgresql logging questions

Hi

I am still a big newbie as far as Postgresql is concerned.
I got some questions about logging.

Most RDBMS's log all sql changes.
When the server crashes or a power failure occurs and the server comes back up
the rdbms rolls back to the nearest checkpoint and does a roll forward from the log.

Does Postgres also do this? If so is Postgres logging any beter than other databases?
How good is Postgres at surviving power failures?
This is of course assuming that you don't have a ups.

Thanks

H.F.

On 01/30/12 12:14 PM, Heine Ferreira wrote:
>
> Most RDBMS's log all sql changes.
> When the server crashes or a power failure occurs and the server comes
> back up
> the rdbms rolls back to the nearest checkpoint and does a roll forward
> from the log.
>
> Does Postgres also do this?
>

yes, although it uses a somewhat different technique than you describe.

>
> If so is Postgres logging any beter than other databases?

'better' is subjective without defined metrics.

> How good is Postgres at surviving power failures?
> This is of course assuming that you don't have a ups.

UPS's fail too :)

assuming your file system and storage hardware are robust and doesn't do
things like lie about write caching, postgres is very good about
recovery to the last committed transaction.


--
john r pierce                            N 37, W 122
santa cruz ca                         mid-left coast