Re: can the behaviour of LocalCheckPoint be changed ?

[Balasubramanian Azhagappan]

Hello Mr.Fisk,
Thank you for your response. I have one more doubt regarding this.

Harrison Fisk wrote:
> The LocalCheckpoint mechanism is how it makes it
> possible to reuse REDO log space that is stored on
> disk. In order to safely remove the log records
> it needs to make sure that all corresponding data
> is written to disk.

I observed the traffic during the Local Check point. As i was populating the tables with 1 Million Entries, the traffic during each LocalCheckPoint is increasing linearly. So, from this i assumed that all the records in the memory are written to the disk and the REDO log space is adjusted. does corresponding rows as you said, refers to only new records or to all ?

> Keep in mind that you can set how often it will do
> the LocalCheckPoint. If it is doing it for one
> row, then you can bump up the setting
> TimeBetweenLocalCheckpoints to cause it to wait
> for more data changes before doing it. The
> default is 4MB, so it shouldn't do it for just a
> single row (unless you changed it).

I am not sure whether LocalCheckPoint runs when the data changes reaches 4MB. If so, then i wonder why the LocalCheckPoint ran even when i did not carry out any tests in the nights, that too it ran for every 1 hour exactly. Is it that the checkPoint interval is not only based on data changes but also on the time interval ? I have not changed the default value of TimeBetweenLocalCheckPoint.

Looking forward to your help. Thanks in advance.

reagrds,
Bala