Re: How to i check how often my redo logs switch??

"Daniel Morgan" <damorgan_at_x.washington.edu> a écrit dans le message de news:1087850967.443153_at_yasure...
> Steve Howard wrote:
>
> > Daniel Morgan <damorgan_at_x.washington.edu> wrote in message news:<1087799515.153873_at_yasure>...
> >
> >>>* can i specify an interval to switch logs?
> >>
> >>No! Resize the log files if you think 30 minutes is some magical
> >>value ... it isn't.
> >>
> >
> >
> > archive_lag_target in 9.x and later.
>
> What is this? I find no object in 9.2.0.4 with that name and no
> column with that name either?
>

ARCHIVE_LAG_TARGET
Parameter type Integer
Default value 0 (disabled)
Parameter class Dynamic: ALTER SYSTEM
Range of values 0 or any integer in [60, 7200]  Real Application Clusters Multiple instances should use the same value.

ARCHIVE_LAG_TARGET limits the amount of data that can be lost and effectively increases the availability of the standby database by forcing a log switch after a user-specified time period elapses.

A 0 value disables the time-based thread advance feature; otherwise, the value represents the number of seconds. Values larger than 7200 seconds are not of much use in maintaining a reasonable lag in the standby database. The typical, or recommended value is 1800 (30 minutes). Extremely low values can result in frequent log switches, which could degrade performance; such values can also make the archiver process too busy to archive the continuously generated logs.

--
Regards
Michel Cadot



> Thanks.

>

> -- 

> Daniel Morgan

> http://www.outreach.washington.edu/ext/certificates/oad/oad_crs.asp

> http://www.outreach.washington.edu/ext/certificates/aoa/aoa_crs.asp

> damorgan_at_x.washington.edu

> (replace 'x' with a 'u' to reply)

>