Originally posted by SANJAY_G
As Pando said, your SORT_AREA_SIZE is too big. If there are 5 sessions doing sorts concurrently, 1 GB of memory will be taken up by this 5 sessions.
Hey, don't scare him too much (or at least tell him the whole story)! If there are 5 sessions doing sorts concurently, then they will allocate exactly that amount of sort memory that is needed for sorting, with 200Mb being the upper limit for each sort. So if those 5 sessions need 2 Mb of sort memory each, they will consume 10 Mb of memory, not 1 GTB. Only if each of them is doing a real massive sort operation requiring 200Mb of sort space they will need 1 Gb (which is highly unlikely, I guess).