Hi All,
I have a need to backup the records from a table before update and for this I want to create a backup table with nologging option, so I can make the backup operation faster. The backup table will have around 2 million records to backup from a master table of around 80 million records; Once this is successfully backed up, I would like to update the main table;
The questions I have on this are:
1. With NOLOGGING option in place, will the database still do it as a single logical work, meaning either all records will be loaded into the table or none at all. I assume it will be treated as a single logical work, so all will be loaded, but please confirm, if my understanding is correct;
2. Can I still get back to the backed up table with full data, just in case I require that data? Is there any chance of corruption of data happening in the backed up table, like some records being lost etc., because of NOLOGGING option? Please note, we will not be inserting any records into this table after the initial CTAS statement;
3. I would like to update the master table only after ensuring the records in the backed up table are greater than 0. This is to ensure backed up table was successfully created, please let me know, if you see any issue with this approach;
Please let me know, if the above approach is fine OR there are some better alternatives.
Thank you.