User, instance, table, table space

Understand

1:oracle

A database can create multiple instances, each of which can create more than one table space, each of which

You can create multiple users under

(the user also belongs to a table space corresponding to the instance)

and database files,

User

Multiple tables can be created (each table is randomly stored in one or more database files), such as:

Understanding 2:

There are users and table spaces under the instance,

The user authorizes access to the table space,

The tablespace is the management data file,

User

Authorized to create tables in a table space, tables are randomly stored in different data files. As shown in the following:

Action 1:

Installation

Oracle

will have a default instance, i.e.

ORCL

。 Typically, multiple instances are not created, under the default instance

Create table spaces and users, and so on.

1, run cmd into the DOS interface, first input: Sqlplus, enter, and then input: Sys/sys as SYSDBA, enter, that is, enter the "sql〉" Operation status.

2, Input: CREATE tablespace tablespace name LOGGING datafile ' C: Table spatial data file. Ora ' SIZE 500M autoextend on next 200m maxsize 2048m;

, table space creation is complete.

3, Input: CREATE user Name profile default identified by user password default tablespace authorized access Tablespace name

Temporary tablespace temp account UNLOCK; The user creates the complete and authorizes the user to access a table space.

The exact operation is as follows:

Action 2:

Create tables and insert data, and query to browse the inserted data.

1, create the table, enter:

CREATE table

Table name

(

Field name

1

Field type

,

Field name

2

Field type

,

Field name

3

Field type

);

Enter.

2, insert data, enter:

INSERT INTO

Table name

(

Field

1,

Field

2,

Field

3) VALUES (

Value

1,

Value

2,

Value

3);

Enter.

3, query data, enter:

SELECT * FROM

Table name

;

Enter.

The exact operation is as follows:

User, instance, table, table space