Getting Started with Oracle

Oracle tablespace Meaning: A tablespace is a logical division of a database, and a table space can belong to only one database. All database objects are stored in the specified table space. But the main storage is the table, so called table space.

there is at least one tablespace in the Oracle database, the table space for the system.

Oracle Database can create multiple DB instances

You can have more than one table space under a database

Multiple users can be in a database, each user can use a different table space

Users, you can create database tables, tables can also be in different table spaces

Tablespace: Creating a table space creates a data file on the physical disk that acts as the physical storage space for database objects (users, tables, stored procedures, and so on);

User: The creation user must specify a tablespace for it, and if there is no explicit specified default tablespace, it is specified as the Users table space, and after the user is created, other database objects, such as tables, stored procedures, and so on, can be created on the user;

Table: is a collection of data records;

Creation process: Table space---> User---> table;

Owning relationship: The table space contains the user inclusion table;

Query DB instance Name:

Select name,v$database.* from V$database;
Select instance_name,v$instance.* from V$instance;

V$database is a dynamic State Performance view, which is a variety of information for the current DB instance.

Query all table space names: select Tablespace_name from Dba_tablespaces;

Query the current user's basic information: SELECT * from User_users;

Query all users that the current user can manage: select * from All_users;

Query all user information: SELECT * from Dba_users; The prerequisite is to have DBA authority for an account, such as Sys,system.

Find out which tables are available under your current User:

SELECT * from User_tables;

Query what tables you can access under your current user [that is, access yourself and other users]:

SELECT * from All_tables;

Querying all tables in the current database requires that you have DBA authority:

SELECT * from Dba_tables;

Getting Started with Oracle