Importance of Parameter File or PFILE:

    During an oracle instance startup, the characteristic features of the instance are configured by the parameters written in a PFILE or Initialization parameter file or Static Parameter file. The PFILE is commonly known as init.ora file among the DBA community. The naming convention for PFILE is initSID.ora and placed in the $ORACLE_HOME/dbs folder in default. PFILE is a txt file and can be edited using an operating system editor like notepad. PFILE is opened only during instance startup. There is an other similar file in oracle server named as SPFILE or Persistent parameter file. SPFILE is a binary file which cannot be opened manually. SPFILE concept is available only from oracle 9i and above versions. For detailed information regarding the parameter files please visit initSID.ora

Example of a PFILE:

      # Initialization Parameter File : inituser.ora
      db_name = user
      instance_name= user
      control_files = (home/user/ORADATA/u01/controluser.ctl)
      db_block_size = 4096
      db_cache_size=4M
      shared_pool_size = 50000000
      java_pool_size =50000000
      max_dump_file_size = 10240
      background_dump_dest = /home/user/ADMIN/BDUMP
      user_dump_dest = /home/user/ADMIN/UDUMP
      core_dump_dest = /home/user/ADMIN/CDUMP
      undo_management = AUTO
      undo_tablespace = UNDOTBS