Post date: 26-Aug-2009 10:39:39
In the previous releases of Oracle (9i and older), the granule size was 4MB when your SGA was smaller than 128MB and 16MB if your SGA was bigger.
This calculation has slightly changed with the 10g release.
Now your granules will be 4MB large if your SGA total size is smaller than 1GB and 16MB large if your SGA is bigger.
Please notice that these sizes are the most common sizes, but can be different with some operating systems. For example on Windows NT the granule size will be 8MB for large SGAs.
You can retrieve information on your granules' size anytime by querying the dynamic view V$SGAINFO.