Oracle--(d) tablespace (tablespace)

Basic Relationship: Database---Table space---data segment---partition---data block


table Space (tablespace)
A tablespace (tablespace) is a logical entity that contains a physical data file that holds all the data available to the database, so the size of the tablespace is also the sum of the size of the data file that contains the data, which is the primary logical storage structure of Oracle.

Tablespace is where the data in the database is stored logically, and a tablespace can contain multiple data files. If the data block configuration pctfree,pctuser,freelist Three configuration if there is a conflict with tablespace configuration, the tablespace will prevail.

A tablespace is a disk area that consists of one or more disk files, and a table space can hold many tables, indexes, or clusters. Each tablespace has a pre-made disk area called the initial interval (initial extent) and then uses the next, until the table space is used, to expand the tablespace, add data files, or enlarge existing data files.

A tablespace is the largest logical structure of an Oracle database, and an Oracle database is logically composed of multiple table spaces, a table space that is subordinate to only one database. There is a tablespace in Oracle called System, which is created automatically when the database is created or installed. Mainly used for storage system data dictionary, process, function, trigger, etc., can also store user's table, index and so on. A tablespace can have multiple data files, but a data file may belong to only one table space.

Table spaces are accessed through v$tablespace.
Sql>desc v$tablespace;
Name Type Nullable Default Comments
--------------------------- ------------ -------- ------- --------
ts# number Y
NAME VARCHAR2 (Y)
Included_in_database_backup VARCHAR2 (3) Y
Bigfile VARCHAR2 (3) Y
flashback_on VARCHAR2 (3) Y
Encrypt_in_backup VARCHAR2 (3) Y
CON_ID number Y

Oracle--(d) tablespace (tablespace)