Difference Between DELETE and TRUNCATE
Introduction
The key distinction between truncate and delete is that the TRUNCATE command does not contain the WHERE clause, despite the fact that it acts similarly to the DELETE command. Another difference between deleting and truncate is that the delete command has a narrower safety net.
DELETE
The where clause is optional, despite the fact that the table name is required. If the WHERE condition is not specified, all of the rows in the specified table will be removed. However, if the WHERE clause is present and the criteria are specified as the rows and columns to remove, the DELETE action will be done only on the specified set of data. In a nutshell, it's critical to take caution when using the DELETE command, since it might result in the entire deletion of all data in a database if the WHERE clause is lacking.
If you're wondering how the delete and truncate commands vary in terms of when to apply them, keep in mind that the DELETE command may be used to remove records from any database - either all records or specific rows - depending on how the WHERE clause is used. It is usual for the DBMS to produce a log of all deleted rows when using the DELETE command. This kind of logging makes it simpler for users to recover from a DELETE command error; however, this is not the case with the TRUNCATE command. Developers and DBAs prefer to use the DELETE command over the TRUNCATE command because they may recover the deleted rows in the event of a mistake.
TRUNCATE
If you're wondering when to use the TRUNCATE command, remember that it's best used when you need to swiftly delete all rows from a table. This is due to the fact that using the Truncate statement in SQL results in very little data being recorded in the system. In contrast to the other related operations, this is an important truncation that deletes difference. The TRUNCATE statement is more efficient. One disadvantage is that each row that is erased is not recorded when it is deleted. This basically implies that it is critical to exercise caution when using the SQL truncate command, since all of the rows in the whole database will be destroyed quickly, and information about each row that is erased may not be recorded.
The good news is that with SQL Server, you can undo a TRUNCATE command, which is not allowed in Oracle. Since a result, it's critical not to use the TRUNCATE statement by accident, as this might result in the loss of a lot of crucial data. The data recovery process is lengthy and inconvenient, necessitating advanced coding and potentially resulting in irrecoverable data loss.
Comparison Table Between DELETE and TRUNCATE
| DELETE |
TRUNCATE |
- All records in the table are deleted. The WHERE clause cannot be used to delete particular entries.
|
- Removes all data and allows you to remove particular items using the WHERE clause.
|
- The DELETE trigger is not activated.
|
- The DELETE trigger is fired.
|
- The identity value is reset.
|
- The identity value is not reset.
|
- Because the transaction log isn't used as often, it's speedier.
|
- Is slower since it first scans the database to count the number of rows to remove before eliminating them one by one. The modifications are recorded in transaction logs.
|
- The row-level lock is used.
|
- The table-level lock is used.
|
- It's not possible to utilise it with indexed views.
|
- It's possible to utilise it with indexed views.
|
- ALTER TABLE permission is required.
|
- The DELETE permission on the table is required.
|
Conclusion
Now that you know the primary distinctions between the truncate delete and drop SQL query commands, keep in mind that TRUNCATE and DROP are DDL commands, while DELETE is a DML command. This distinction between delete, truncate, and drop will aid you in evaluating the use and ramifications of these commands. So, although the DELETE command may be used to remove one or more rows from a database, you may need to use the TRUNCATE command to reset a table in certain circumstances. Please contact us if you have any further questions that have not been addressed despite our best efforts to provide a complete comparison of SQL's delete, drop, and truncate commands. We'd also want to hear your thoughts on the differences between the truncate and delete commands.
