Oracle Getting Started notes

Reference material "Oracle in Layman's"

Interest + diligence + Persistence + method ≈ Success

Four rules of DBA survival

1. The backup is heavier than everything else;

2. Think twice;

3.RM is dangerous;

4. You have to make the specification;

Chapter One: Database Startup and shutdown:

Oracle server consists of two main components: Instance and Database.

Instance refers to a set of background processes/threads and a piece of shared memory area, whereas database is a set of physical files stored on disk.

1.1 Startup of the database:

Three boot steps:

1. Start the database inverted nomount state;

2. Start the database inverted mount state;

3. Start the database to open state;

1.1.1 Starting the database to the Nomount state

In the first step of the launch, Oracle first looks for the parameter file (pfile/spfile), then creates the instance, allocates memory, and starts the background process based on the 3 settings in the parameter file.

As long as you have a parameter file, you can start the instance (Instance), this step does not require any control file or data file participation.

When creating a database, if there is a problem with this step, then there is usually a problem with the system configuration (kernel parameters, etc.) and the user needs to check if sufficient system resources are allocated.

Oracle Getting Started notes