PostgreSQL - TRUNCATE TABLE - GeeksforGeeks

PostgreSQL - TRUNCATE TABLE

Last Updated : 15 Oct, 2026

The TRUNCATE TABLE statement in PostgreSQL is used to quickly remove all rows from one or more tables while keeping the table structure, indexes and constraints unchanged.

  • Faster than the DELETE statement because it does not scan individual rows.
  • Can truncate one or multiple tables in a single statement.
  • Is fully transactional in PostgreSQL and can be rolled back if executed within a transaction.

Note: By default, identity (auto-increment) values are preserved, but they can be reset using RESTART IDENTITY.

Syntax

TRUNCATE TABLE table_name
[RESTART IDENTITY | CONTINUE IDENTITY]
[CASCADE | RESTRICT];

Where:

  • table_name: The name of the table to be truncated.
  • RESTART IDENTITY (optional): Resets identity (auto-increment) columns.
  • CONTINUE IDENTITY (optional): Keeps the current identity values (default).
  • CASCADE (optional): Truncates all tables that reference the specified table.
  • RESTRICT (optional): Prevents truncation if foreign-key references exist (default).

Examples

Firstly, create an employee table and insert some records into it.

Screenshot-2026-07-09-143701

Example 1: Truncate a Single Table

The following query removes all rows from the employee table while preserving its structure.

Query:

TRUNCATE TABLE employee;

Output:

Screenshot-2026-07-09-143843
  • The employee table becomes empty, but its structure, indexes and constraints remain unchanged.

Example 2: Truncate Multiple Tables

The following query removes all rows from the employee and Departmendepartment tables in a single statement.

Query:

TRUNCATE TABLE employee, department;

Both tables are emptied while preserving their structures.

Example 3: Truncate a Table with RESTART IDENTITY

The following query removes all rows and resets the identity (auto-increment) values.

Query:

TRUNCATE TABLE employee RESTART IDENTITY;

All rows are removed and identity values are reset to their starting values.

Example 4: Truncate a Table with Foreign Key (CASCADE)

If another table references the employee table through a foreign key, use the CASCADE option.

Query:

TRUNCATE TABLE employee CASCADE;
  • The employee table and tables referencing it through foreign keys are also truncated when CASCADE is used.

Troubleshooting TRUNCATE TABLE Issues

  • Foreign key dependency: Use CASCADE or truncate the child table before the parent table.
  • Identity values not reset: Use RESTART IDENTITY if you want auto-increment values to start from the beginning.
  • Permission denied: Ensure you have the required privileges to truncate the table.
  • Data loss warning: TRUNCATE TABLE permanently removes all rows. Consider creating a backup before executing the command.
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