The open_cursors initialization parameter sets the maximum number of cursors that each session can have open. If open_cursors is set to 100, for example, each session can have up to 100 cursors open at one time. If a session with 100 open cursors attempts to open a session, it encounters ORA-1000 error — “Maximum open cursors exceeded.”
The default value for open_cursors is 50, but Oracle recommends that, for most applications, the value be set to a minimum of 500.