- Dedication
- Preface
- I. DBA Tasks
- 1. Introduction
- 2. Installation
- 3. Maximizing Oracle Performance
- 4. Preventing Data Loss
- 5. Oracle Networking
- Oracle Names
- MultiProtocol Interchange
- Connecting to Non-Oracle Databases
- Network Manager Data Storage
- Using Network Manager
- Files Created by Network Manager
- Oracle Net8 Assistant
- Manual Network Configuration
- Sample SQL*Net Files
- SQL*Net Troubleshooting
- 6. Security and Monitoring
- 7. Auditing
- 8. Query Optimization
- 9. Oracle Tools
- 10. The Oracle Instance
- 11. The Oracle Database
- 12. Initialization Parameters
- 13. SQL Statements for the DBA
- SQL Commands by Task
- SQL Command Syntax
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- Reference Section
- column_constraint_clause
- auto_extend_clause
- for_clause
- filespec
- autoextend_clause
- global_index_clause
- local_index_clause
- table_constraint_clause
- table_ref_clause
- column_ref_clause
- column_constraint_clause
- index_organization_clause
- segment_attrib_clause
- partition_clause
- autoextend_clause
- 14. The Oracle Data Dictionary
- Static Data Dictionary Views
- Dynamic Performance Data Dictionary Views
- 15. System Privileges and Initial Roles
- 16. Tools and Utilities
Name
TRUNCATE TABLE
Synopsis
TRUNCATE TABLE [schema.]table_name[{PRESERVE | PURGE} SNAPSHOT LOG [{DROP | REUSE} STORAGE]
Removes all rows from a table (table_name).
Keywords
- PRESERVE SNAPSHOT LOG
Keeps the contents of any snapshot log associated with the table. This allows you to reorganize the table without losing the snapshot log. This is the default.
- PURGE SNAPSHOT LOG
Cleans out the snapshot log along with the table.
- DROP STORAGE
Deallocates the storage used by the rows and returns the space to the free space pool. This is the default.
- REUSE STORAGE
Retains the space used by the deleted rows. This is useful if the table or cluster will be reloaded with data.
Notes
The table to be truncated must be in your schema, or you must have the DROP ANY TABLE privilege to truncate a table in another schema. The TRUNCATE command does not create rollback records, so it cannot be rolled back. This characteristic makes TRUNCATE extremely fast, and it is preferable to DELETE FROM unless the rollback capability is required. When a table is truncated and the DROP STORAGE clause is specified, only the initial extent of the table is retained; all other storage is deallocated.
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