Re: Thread 1 cannot allocate new log

Hi Anne,

This means that checkpoints are occuring too often. During checkpoints, all data in the buffer cache is flushed to disk, and the headers of the datafiles and controlfiles are updated. This aids us during recovery. Checkpoints also cause a substantial overhead if you have a lot of datafiles. Checkpoints are controlled by the init.ora parameters LOG_CHECKPOINT_INTERVAL (will cause checkpoint after this many OS blocks are written) and LOG_CHECKPOINT_TIMEOUT (will cause checkpoint after this many seconds). They also HAVE to occur at every redo log switch. In your case, if your redo logs are too small and there is a lot of activity in the database, the logs switch very fast and consequently cause checkpoints to occur. Before one checkpoint can complete, another log switch occurs, triggering another checkpoint, and so on. With this message, Oracle is telling you that since the logs are switching so fast, it could not complete the checkpoint that had started at the previous log switch. So the solution to this is to increase the size of your redo logs and have a minimum of three groups so that redo logs will not switch so fast.

Hope that helps.

Murali  

Anne Williamson <annew_at_mac.com> wrote in message news:<3B1C4BC6.A8B58763_at_mac.com>...
> Yesterday I was doing a schema update on my test database, using scripts
> supplied by the third party who supplies the end-user application.
> Looking at the alert log I noticed a number of messages like this:
>
> Thread 1 cannot allocate new log, sequence 1609
> Checkpoint not complete
>
> There is no Oracle error message reported. I couldn't find anything
> about it in the Oracle error messages manual. The scripts all seemed to
> complete happily.
>
> Does anyone know what is causing these messages? How do I stop them?
> What is the result of these incomplete checkpoints?
>
> Digital Unix 4.0F, Oracle 8.0.5.1.1
>
> Many thanks in advance
Received on Tue Jun 05 2001 - 14:47:55 CDT