What is difference between TRUNCATE & DELETE
Answer posted by Scott on 2005-05-25 18:30:04: TRUNCATE is a DDL command and cannot be rolled back. All of the memory space is released back to the server.
DELETE is a DML command and can be rolled back.
Both commands accomplish identical tasks (removing all data from a table), but TRUNCATE is much faster.
Editorial / Best Answer
Answered by: Prangya Sahu
1>TRUNCATE is a DDL command whereas DELETE is a DML command.
2>TRUNCATE is much faster than DELETE.
Reason:When you type DELETE.all the data get copied into the Rollback Tablespace first.then delete operation get performed.Thatswhy when you type ROLLBACK after deleting a table ,you can get back the data(The system get it for you from the Rollback Tablespace).All this process take time.But when you type TRUNCATE,it removes data directly without copying it into the Rollback Tablespace.Thatswhy TRUNCATE is faster.Once you Truncate you cann't get back the data.
3>You cann't rollback in TRUNCATE but in DELETE you can rollback.TRUNCATE removes the record permanently.
4>In case of TRUNCATE ,Trigger doesn't get fired.But in DML commands like DELETE .Trigger get fired.
5>You cann't use conditions(WHERE clause) in TRUNCATE.But in DELETE you can write conditions using WHERE clause.
- Transformer based ups vs transformer less ups
- Vpn and vlan
- Difference beetween ppc & opc
- Credit memo and debit nemo in AR and ap
- Dynamic cache
- Delete duplicate records
- Difference between impicit index and explicit cursor
- Windows 2000 vs windows 2000 server
- Half controlled and full controlled rectifier
- Log sequence number and checkpoint id
- Filters and restricted columns
- Difference between mobile app testing and mobile app native testing
- Etl case and decode
- Product testing on various versions of hardware.
- Pre-emtive and non-pre-emtive scheduling
- Horizontal and vertical clustering
- Mobile and desktop testing
- RMAN logical and physical backup
- Find function and query find function