oracle tablespace is different

Oracle database is a powerful relational database management system that can store a large amount of data. However, as the data continues to grow, it will lead to the problem of insufficient table space, which requires the management and maintenance of table space. In Oracle, there are different types of table spaces, and this article will discuss the differences between them and how to manage these table spaces.

1. Ordinary table space

Ordinary table space is the most common table space type in Oracle. They are physical files defined to store data tables and indexes. Ordinary table spaces include:

1. Data table space: used to store data in data tables and views.

   2. Index table space: used to store index files, including B-Tree indexes, bitmap indexes, and hash indexes.

Ordinary table spaces are often used to store business data and index information. They are used by default when creating a new table or index.

2. System table space

The system table space is the default table space for saving Oracle system files, and the management system must rely on it. It includes:

1. SYSTEM table space: It saves the metadata information of the database, including system-level elements such as tables, indexes, constraints, stored procedures, and triggers.
2. SYSAUX table space: Saves additional metadata information, including AWR reports, RMAN backup sets, Oracle Text indexes, etc.
3. UNDO table space: saves rollback segments and is used to restore to a previous transaction state.
4. TEMP table space: Saves the data of temporary tables. These tables are created during the query process and are used for comparison, sorting, aggregation and other operations.

The system table space is usually created and managed by the DBA and is not open to ordinary users. If the system table space is full, the database will not work properly and therefore needs to be cleaned regularly.

3. Temporary table space

Temporary table space is created to handle the needs of sorting operations and temporary tables. It is commonly used to store calculation results and data sorting. Because the data used for sorting using a temporary tablespace is short-lived, it can be deleted after the processing operation is completed.

Temporary table spaces are usually set up and managed by the DBA. If the temporary table space is full, it needs to be emptied regularly.

4. Undo table space

The undo table space is an important part of managing Oracle transactions. It is responsible for storing all modification operations of the current session and transaction so that they can be recovered when these operations are undone. This undo information will be saved in the rollback segment in the undo table space and can be used to roll back, restore or change a transaction.

The undo tablespace is a very busy tablespace because it is often the target of multiple sessions and transactions. In each transaction, the size of the undo tablespace will increase and occupy virtual memory resources. An excessively large undo table space will have a negative impact on database performance, so it needs to be managed and cleaned regularly.

5. Recycle Bin Table Space

The recycle bin table space is a new table space in Oracle 10g. It is used to store deleted objects. These objects can be restored to the database. middle. When objects are deleted, they are not deleted directly from the database but are stored in the recycle bin tablespace. The retention time of Recycle Bin objects can be configured so that restore operations can be performed later.

The recycle bin table space can make it easier for administrators to manage the deletion and restoration of objects. However, if the recycle bin table space is too large, it may have a negative impact on database performance and require management and cleanup.

To sum up, there are different types of table spaces in Oracle, and each table space has different functions and management requirements. When the table space is insufficient, corresponding measures must be taken for management and maintenance to ensure the normal operation of the database. Administrators should understand the differences between different types of table spaces and how to manage them to maintain database health and reliability.

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