I'd just seen In ORAOCI8, in update action, two choices :
- clear table then insert rows
- truncate table then insert rows
What are differences ?
Difference between Clear and Truncate
Moderators: chulett, rschirm, roy
Re: Difference between Clear and Truncate
Besco,besco wrote:I'd just seen In ORAOCI8, in update action, two choices :
- clear table then insert rows
- truncate table then insert rows
What are differences ?
Both the Update actions' functionality is the same.
But, the former action deletes the contents of the table and adds
the new rows, with slower performance because of transaction
logging. Whereas, the later truncates the table without transaction logging and hence faster performance.
P.S. Refer Datastage's help.
Regards,
Bhanu.
Hi,
I just want to add to Bhanu's comments.
Clear/Delete: For every delete an entry is made in the transaction log.
Advantage:You have the posibility of rollback
Disadvantage:Slower compared to Truncate since it has to make an entry in the transaction log
Truncate: No entry is made in the transaction log.
Advantage:Faster since no entry is made in the transaction log
Disadvantage:You cannot rollback since it is a Data Definition command.
HTH
Rich
I just want to add to Bhanu's comments.
Clear/Delete: For every delete an entry is made in the transaction log.
Advantage:You have the posibility of rollback
Disadvantage:Slower compared to Truncate since it has to make an entry in the transaction log
Truncate: No entry is made in the transaction log.
Advantage:Faster since no entry is made in the transaction log
Disadvantage:You cannot rollback since it is a Data Definition command.
HTH
Rich
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