Re: Extended checkpoint times

anonymous wrote: > > Hi, > > We are trying to investigate a series of overly long checkpoints on > one of our informix databases, here is a snippet of the online.log > file detailing the events: > > 21:16:55 Checkpoint Completed: duration was 76 seconds. > 21:22:04 Checkpoint Completed: duration was 6 seconds. > 21:27:16 Checkpoint Completed: duration was 8 seconds. > 21:40:15 Checkpoint Completed: duration was 476 seconds. <SNIP>> Are there commands available to analyze the log files to see which sql > statements were running upto when the checkpoint took place - > or if you know of anything that could cause these kinds of checkpoint > times that would be useful. Last time I ran into a similar problem, I did the following command: $ onstat -FR -r 1 >>onstat.FR.out & This way I could review the output and watch how the LRU queues grew more & more dirty. But more important, I could see ~ how fast the buffer queues are getting cleaned up while a checkpoint is in progress. When it turned out to 75 buffers/sec my client needed an exorcist! I also recall I had written an AWK script to summarize the onstat -R part for clean/modified/total buffers each step of the way. -- -- Jake (Never yelled "CROWDED THEATER!" during a fire) +------------------------------------------------------------+ | The expedient performance of a task with excessive concern | | regarding its duration-to-completion engenders a virtual | | certainty of diminished benefit therefrom. | | -- Benjamin Franklin (but he said it in 3 words) | +------------------------------------------------------------+