My Oracle Notes (5): various names in Oracle

Such as the database name, database instance, SID ......

Oracle_SID

SID is the abbreviation of System IDentifier (also known as Site IDentifier), and Oracle_SID is the abbreviation of Oracle System IDentifier. in Oracle, Oracle_SID appears in the form of environment variables. When an Oracle instance is started, the fork process on the operating system is created based on this Oracle_SID. This is the role of SID.

INSTANCE_NAME

An initialization parameter INSTANCE_NAME exists in the Oracle database to identify the database instance name. The default value is ORACLE_SID. However, the initialization parameters INSTANCE_NAME and ORACLE_SID can be different, and different instances can have the same INSTANCE_NAME.

 

 

Alarm Log File

The alarm log file consists of messages and error records in chronological order.

The following information is recorded in the alarm log file:

(1) internal errors (ORA-600, ORA-07445 and other errors) and block damage errors (ORA-1578 );

(2) operations that affect the DATABASE structure and parameters and statements such as create database, STARTUP, SHUTDOWN, archive log, and RECOVER

(3) All non-default initialization parameter values at instance startup

It is important for the database administrator to regularly check the alarm log files so that they can be found and processed in a timely manner before the problem becomes serious.

Because the alarm log files are accumulated constantly, you can back up or sort the alarm log files after the check. The storage location of the alarm log file is defined by the initialization parameter BACKGROUND_DUMP_DEST.

You can use select value from v $ parameter where name = 'background _ dump_dest '; to find its specific address.

 

 

References:

(1) Chapter 1 of in-depth Oracle Analysis

(2) Oracle9i. Database. Administration. Fundamentals

(3) Ask Tom "What is a SID, how to change it, how ..."