Re: Why does an online redolog keeps active after checkpoint completion?

quarkman <quarkman_at_myrealbox.com> schreef in berichtnieuws oprta1dwt1zkogxn_at_haydn...
| On Sat, 2 Aug 2003 20:37:42 +0200, Anton Buijs
<remove_aammbuijs_at_xs4all.nl>
| wrote:
|
| > |
| >
| > You are right. I varied the value of log_checkpoint_timeout in my
| > playground
| > database and the status active becomes inactive after a period of time
| > that
| > is related to the timeout period. Lgwr is choosing priorities as you
| > described. I get the impression it also depends on the load on the db.
My
| > tests where the only active sessions. When I do some (update) work the
| > active status disappears also much quicker.
| > Thanks.
|
| It should be pointed out, however, that setting L_C_TIMEOUT is not a
| particularly good idea. In 8i, you have L_C_INTERVAL and
| FAST_START_IO_TARGET to work with to make instance recovery time extremely
| predictable. And in 9i, you have FAST_START_MTTR_TARGET to use, which
| internally gets converted into settings for _IO_TARGET and _INTERVAL -but
| not for _TIMEOUT. Which gives the game away: _TIMEOUT is not particularly
| useful in limiting instance recovery times in a predictable fashion.
|
| In the absence of _TIMEOUT, behaviour is as I described earlier: another
| log switch will cause the original log's status to be updated.
|
| ~QM

You are right. I know how to set these parameters. But for the purpose of testing and insight in this behaviour I used an absolutely wrong value for log_checkpoint_timeout of 10 and 30 sec. Just to observe the behaviour. But thanks for your concerns. Received on Sun Aug 03 2003 - 04:46:10 CDT