Table space management in DB2 (1)

The tablespace is the logical layer between the database and the tables stored in the database. Create a tablespace in the database and a table in the tablespace.

One obvious advantage of using tablespaces is that data can be reasonably distributed and stored on different disks or in different locations on disks, which helps improve data access efficiency.

DB2 tablespaces are managed in two ways: System Management Space (System Management Space) and Database Management Space (DMS ).

By type: Rule tablespace, large object tablespace, system temporary tablespace, and user temporary tablespace.

The table that contains user data in the Rule tablespace. The Default User tablespace name is USERSPACE1, and the index is also stored in the Rule tablespace. In addition, the system directory table is also stored in the Rule tablespace. The default system directory tablespace is SYSCATSPACE.

Temporary tablespace is divided into system temporary tablespace and user temporary tablespace.

The system temporary tablespace is used to store the internal temporary data required in various data operation sorting, table reorganization, index creation, and table connection). Although you can create any number of system temporary tablespaces, however, we recommend that you only create one table with the page size used by most tables. The default temporary tablespace name is TEMPSPACE1.

The user temporary tablespace is used to store the temporary data of the application ). The user's temporary tablespace is not created by default during database creation.

Each SMS container is a directory in the file space of the operating system. Each DMS container is a fixed, pre-allocated file, or physical device.

The management of SMS is relatively simple and is automatically managed by the operating system. The size of the space is automatically adjusted as the data volume changes.

DMS is managed by databases. The size of the space is determined during creation. When the space is insufficient, you must manually add or delete some data to release the space.

In most cases, DMS performs better than SMS.

Simple syntax for creating SMS tablespace using command line:

CREATE TABLESPACE Managed by system using (' ')

★Example 1: Create an SMS tablespace on Windows: