Oracle Architecture

SPFile – binary file written to and read by the DB. Must not be edited manually. Default filename is $ORACLE_HOME/dbs/spfile.ora.

SYS> show parameter spfile;

spfile string /u01/app/oracle/product/10.2.0

/db_1/dbs/spfileorcl.ora

Text initialization parameter file – read by DB but not written to by the server. Default name is init.ora

SYS> create pfile from spfile;

File created.

[oracle@localhost dbs]$ pwd

//u01/app/oracle/product/10.2.0/db_1/dbs

[oracle@localhost dbs]$ ls -lrt

total 52

-rw-r----- 1 oracle oinstall 8385 Sep 11 1998 init.ora

-rw-r----- 1 oracle oinstall 12920 May 3 2001 initdw.ora

-rw-rw---- 1 oracle oinstall 1544 Jan 23 18:33 hc_orcl.dat

-rw-rw---- 1 oracle oinstall 24 Jan 23 18:33 lkORCL

-rw-r----- 1 oracle oinstall 1536 Jan 23 21:38 orapworcl

-rw-r--r-- 1 oracle oinstall 56 Jan 24 11:50 alert_orcl.log

-rw-r--r-- 1 oracle oinstall 1052 Feb 15 15:03 initorcl.ora

-rw-r----- 1 oracle oinstall 3584 Feb 15 15:04 spfileorcl.ora

[oracle@localhost dbs]$

Password file - $ORACLE_HOME/dbs/orapworcl

connect hr/hr@orcl, this will check the password in the system tablespace data dictionary

Control file – store database file location, redo log location, checkpoint. Save each file to separate disk for redundancy