Difference and contact Oracle table space, user and tables

Difference and contact Oracle table space, user and tables

• Oracle database is used to store those tables, indexes, views actually exists through the table space,
  • Table space Category:
    1. Temporary table space: a database for storing a single model of persistent objects, such as tables, indexes, views, etc., the data corresponding to one or more data files physically. Permanent table space is what we actually used a type of most of the table space.
    2. Permanent table space: objects can not be stored permanently. Its main purpose is to store temporary data tables, providing space for sorting operation, creating indexes.
    3. Undo table space: undo table space is mainly used for data management DML statements, when performing insert, update, delete the old data will be stored in the undo table space.
       1. 4 Common undo tablespace
          
          1. 　　Transaction rollback
          2.         Database Recovery
          3.         Read consistency
          4. 　　Flashback Query
• A database instance may contain a plurality of table space, and may store a table space multiple tables

 

• Each user generally has a default permanent tablespace and a temporary table space
• A user can have permission to live a more table space

 

　　Different roles of table creation statements may differ:

　　　　　　create table test (id int); table thus created, will be created in the user's default tablespace.

　　　　　　create table test1 (id int) tablespace Test01; table thus created, will be created in the space table Test01.