Fragmented SGA

[anuragmin]

Hi,
How does one find whether the SGA is fragmented or not.

I tried looking in the docs but could not find an answer .

Thanks
Anurag

[sambavan]

Since SGA is dynamically allocated area, which comprises of all kinds of components like, shared_pool, buffer cache, java pool, and log buffer. Finding the doc for the fragmentation is kind of hard. Infact, bouncing the instance would be the only way to remove the SGA fragmentation, as multiple processes gets opened and closed, SGA is more likely fragmented most of the time. Places that you want to look are fragmentation on the disk, which is the most culprit, and would consume most of the time. Memory fragmentation weighs only a tiny part on the performance.

For more detail, refer the Performance tuning documentations. Yeah, I know I'm very wague and hope that this would help you.


Sam