Check whether the number of existing processes in the database has reached the processes parameter -- select count (*) from v $ process; to obtain the current number of processes in the database. -- Select value from v $ parameter where name = 'processs'; obtain the maximum number of processes (1) view the current number of sessions, processes, and sessions values, it is found that the number of sessions 14 and the processes value 150 are very close to SQL> select count (*) from v $ session; COUNT (*) ---------- 146 SQL> show parameter processes NAME TYPE VALUE when using aq_tm_processes integer 0 then integer 2 gcs_server_processes integer 0 job_queue_processes integer 10 then integer 2 processes integer 150 (2) Modify the two parameter (processes, sessions) SQL> alter system set processes = 300 scope = spfile; System altered. SQL> alter system set sessions = 335 scope = spfile; System altered. (3) Let's shutdown and startup database in order to let the two parameter taken effect. SQL> shutdown immediate; Database closed. database dismounted. ORACLE instance shut down. SQL> startup ORACLE instance started. total System Global Area 1610612736 bytesFixed Size 2030456 bytesVariable Size 989856904 bytesDatabase Buffers 603979776 bytesRedo Buffers 14745600 bytesDatabase mounted. database opened. SQL> exitDisconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.3.0-64bit ProductionWith the Partitioning, OLAP and Data Mining options $ sqlplus/nolog (4) test the result. SQL * Plus: Release 10.2.0.3.0-Production on Friday December 9 09:53:13 2011 Copyright (c) 1982,200 6, Oracle. all Rights Reserved. SQL> conn sys/oracle @ orcl as sysdbaConnected. SQL> -- the end.