What is an instance of oracle

An oracle instance is some database program that supports the running of the database.

It consists of multiple background processes of the operating system and a pool of ****enjoyed memory, which is accessible to all processes.

Oracle manages database access on an instance-by-instance basis. Users who want to access data in the database (that is, files on the hard disk) must do so through an Oracle instance, and cannot read files on the hard disk directly.

In fact, Oracle instance is usually called database services (service).

At any given moment an instance can only be associated with one database, accessing one database; while the same database can be accessed by multiple instances (RAC).

Extended information

Features of oracle database:

1. Complete data management functions:

1) large amount of data

2) data preservation of the durability

3) data **** enjoyment

4) data Reliability

2, the product of the complete relationship:

1) information guidelines - all information in a relational DBMS should be logically represented in one way, that is, the values in the table explicitly;

2) guaranteed access to the guidelines

3) view updating guidelines - as long as the data in the table that forms the view has changed, the data in the corresponding view change at the same time

4) data physical and logical independence guidelines

3, distributed processing capabilities:

ORACLE database since version 5 provides distributed processing capabilities, to version 7 has a more complete distributed database capabilities, an ORACLE distributed database by oracledbms, sql * Net, SQL*CONNECT, and other non-ORACLE relational products.

4, with ORACLE can easily realize the data warehouse operations.

Baidu Encyclopedia - Examples

Baidu Encyclopedia - Oracle database