Can I disable logging for session in Oracle 10g?

Question

I use a procedure to delete a lot of row for an application repeatedly. Because the DELETE statement is time consuming and the data don't need to be archived, I decide to use the nologging option.
How to do it?
What is the best choice? Can I disable logging from session in Oracle 10g?
Thank you
Edited by: jetq on Jul 23, 2009 9:46 AM

Answer 1

Hi,
"Delete" without generating redo-log is not possible.
If you are on 10g, one way of making this thing efficiant is partition the table, with range-list partitioning. Partitioning existing table will be an excercise in itself, but that will be one time activity.
In partitioned (or sub-partitioned) tables, you can truncate a partition (or subpartition). That won't generate any redo log (or very very less redo log) and that runs in seconds.
In your case if you range partition INCOMING table by datetime (1 partition per day) and list sub-partition it by STATUS, that would help.
Another approach is, if you are deleteing, say 80% records every day and leaving 20% (or very less) records. What you can do is, partition the table only by range on datetime. Then, every time you want to delete data, copy the rows you want to keep in some other table (or temporary table), truncate partition for that day and insert rows back (which you want to keep).
I have done a similar thing and it works very quickly and generates very less redo log. Redo log generated in case of truncating partition or creating new partitions is just for Oracle internal commands (like data dictionary update etc).
Have fun.