Disable redo log generation generation before bulk load of data

Redo logs are there for recovering your database in the event of a crash or an OS file corruption. If you don't have redo logging on, then if anything goes wrong with the database your users will lose all their work since the last good back up.Not logging in a transactional system is a very bad idea.

But in some circumstances you can disable redo log generation without worries and improves performance

• In test environment
• bulk load of data
• creating/recreating of indexes

The NOLOGGING mode improves performance because it generates much less log data in the redo log files helping in eliminating the time needed to execute the redo generation (latch acquisition, redolog writing, etc.). The user is responsible for backing up the data after a NOLOGGING insert operation in order to be able to perform media recovery.