Skip to content
When you create a database, there are default users such as SYS and SYSTEM, and the passwords are set when the database is created. The passwords can be changed and managed with security policies.Here is the list of the administrative user accounts:• SYS• SYSTEM• SYSBACKUP• SYSDG• SYSKM• SYSRAC Administrative accounts have special permissions required to […]
There are a few types of users for the Oracle Database. We have already mentioned a few of them that were needed to install the software and create the database. Depending on the size of the environment and how many people are available to manage the environment, there might be the same person in each […]
Depending on your business requirements, you may need a strategy for backing up archive redo log files. Minimally, you should back up any archive redo logs generated during a backup of a database in archivelog mode. Additional strategies may include the following: • Periodically copying archive redo logs to an alternate location and then removing […]
After you have set the location for your archive redo log files, you can enable it as SYS with the following: You can confirm archivelog mode with this query: You can also confirm it as follows: Disabling Archivelog Mode Usually, you don’t disable archivelog mode for a production database. However, there might be a reason […]
Before you set your database mode to archiving, you should specifically instruct Oracle where you want the archive redo logs to be placed. You can set the archive redo log file destination with the following techniques: • Set the LOG_ARCHIVE_DEST_N database initialization parameter. • Implement FRA. These two approaches are discussed in detail in the […]
When you implement archivelog mode, you also need a strategy for managing the archived log files. The archive redo logs consume disk space. If left unattended, these files will eventually use up all the space allocated for them. If this happens, the archiver cannot write a new archive redo log file to disk, and your […]
For some types of applications, you may know beforehand that you can easily re-create the data. An example might be a data warehouse environment in which you perform direct path inserts or use SQL*Loader to load data. In these scenarios you can turn off the generation of redo for direct path loading. You use the […]
If you determine that you need to add an online redo log group, use the ADD LOGFILE GROUP statement. In this example, the database already contains two online redo log groups that are sized at 200M each. An additional log group is added that has two members and is sized at 200MB: With ASM, the […]
Oracle requires at least two redo log groups to function. But, having just two groups sometimes isn’t enough. To understand why this is so, remember that every time a log switch occurs, it initiates a checkpoint. As part of a checkpoint the database writer writes all modified (dirty) blocks from the SGA to the data […]
Use the V$LOG and V$LOGFILE views to display information about the online redo log groups and corresponding members: Here is some sample output: When you are diagnosing online redo log issues, the V$LOG and V$LOGFILE views are particularly helpful. You can query these views while the database is mounted or open. The STATUS column of […]
