onstat -u ....waiting on condition

Hi I was just looking at the output from onstat -u 3b706d2c Y--P--- 97984 3b70d958 Y--P--- 121881 3b710860 Y--P--- 100957 3b71167c ---P--- 121893 3b711fe4 Y--P--- 113791 3b71b1b0 ---PR-- 121842 3b7230ac Y--P--- 100952 3d96c014 S--PR-- 121894 3d96fd38 Y--P--- 104413 3d9714bc Y--P--- 100969 3d971970 Y--P--- 121886 3d9793b8 Y--P--- 121398 3d97d590 Y--P--- 100971 3d97f67c Y--P--- 104416 3d9820d0 Y--P--- 120764 3d982eec Y--P--- 121380 3d984fd8 S--PR-- 121890 3d986c10 Y--P--- 100991 3d989fcc S--PR-- 121892 3d98ced4 Y--P--- 100959 Can anyone tell me what the Y in the first coloumn indicates I know it is waiting on condition but is it waiting on the condition in the sql statement or on a database condition? Also I am now seeing a S in the first column (never had this before - we have just started running several invoices at the same time). I read up on the S and it is a mutex - mutually exclusive latching mechanism that the database uses to synchronise access by multiple threads to shared resources - so now in English does this mean it is a thread that can't use a resource like a buffer because there aren't any left or because another thread is using it? Or am I totally heading in the wrong direction? Also if it is waiting to use a shared resource - how can I monitor what resource it is (ie. memory, i/o etc)? Thanks in advance Bridget