SQL DELETE vs TRUNCATE TABLE: The best choice to clear tables

The best choice for clearing tables is usually TRUNCATE TABLE, which is faster than DELETE and does not trigger foreign key cascade deletion. The best choice for specific situations is as follows: Delete is required to delete data in a condition: Use DELETE. Need to trigger foreign key cascade deletion: use DELETE. Need to quickly clear the entire table: Use TRUNCATE TABLE. Need to avoid foreign key cascade deletion: Use TRUNCATE TABLE.

SQL DELETE vs TRUNCATE TABLE: The best choice to clear tables

Short answer:

The best choice for clearing tables is usually TRUNCATE TABLE, as it is faster than DELETE and does not trigger any foreign key cascade deletion.

Detailed explanation:

DELETE

• Delete rows in the table that meet the specified criteria.
• Preserve the table structure and index.
• Triggering foreign key cascade deletion, which may have an impact on other tables.
• Used when it is necessary to delete data conditionally.

TRUNCATE TABLE

• Delete all rows from the table, including data and empty space.
• Keep the table structure, but reset the index.
• Foreign key cascade deletion is not triggered.
• The speed is faster than DELETE when clearing the table.

Choose the best option:

• Use DELETE when:

  • A specific row needs to be deleted conditionally.
  • Foreign key cascade removal needs to be triggered.

• Use TRUNCATE TABLE when:

  • The entire table needs to be cleared.
  • No need to trigger foreign key cascade deletion.
  • Requires faster operation than DELETE.

Notes:

• TRUNCATE TABLE Cannot roll back.
• If there is a foreign key association on the table, the foreign key constraints should be paused before using TRUNCATE TABLE.
• For large tables, TRUNCATE TABLE is more efficient than DELETE because its performance is independent of the table size.

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