Page History
...
The results should be that the " Extent Scan Fragmentation " is less than 50 and the " Logical Scan Fragmentation " is low; otherwise, it will damage the index scans.
...
| Info |
|---|
Be aware that the index and the table will not be available is unavailable during the rebuild. |
Backing up the database and creating archiving
...
If you choose the simple recovery mode for the database (the transaction log can be deleted after a commit or checkpoint), the recovery will not be able to cannot work to a point in time, but only to the backup time.
...
If you do not create a backup, information will be is lost when you have a database crash and you will not be able to cannot recover data.
Additional DBA settings for an SQL Server-based PMDB
...
| Parameter | Value | Improvement | |
|---|---|---|---|
| db_block_size | Minimum 8 KB (16 KB recommended) | This value defines the Oracle block size. The block size is set when creating the database and cannot be changed afterwards. A value of at least 8 KB ensures that the PMDB can perform smoothly. A lower value may cause serious performance problems. If you are installing on a legacy database, verify that the database block size is 8 KB or higher. If not, try to install the PMDB on a different Oracle instance. infoThe default block size on Windows NT is 2 KB, which is too small. To review this value, check the |
Required INIT.ORA changes
...
| Parameter | Value | Improvement / Remarks |
|---|---|---|
sga_target | Automatic memory management. 1/4th One quarter of the physical memory. | Replaces the following parameters:
Verify that they are initialized with either 0 or the minimum value you need. |
...
The PMDB holds information for up to 3 three years by default. If you want to backup this information, you should enable the Redo log archiving, and create a backup using RMAN. For more information, refer to the official Oracle Backup and Recovery documentation. If you do not create a backup, information will be lost when you have a database crash and you will not be able to recover data. If you create a backup without using the archive mode, you will be able to recover data to the time of the backup. All new operations (after the logs were archived) will be lost.
...
To enable Automatic Undo Management (AUM), you must create a new tablespace and set the init.ora parameters. For additional information on how to enable AUM, see the Oracle Database Administrator's Guide, "Managing Undo Space."
To enable Automatic Undo Management (AUM)
- Create the
undo tablespaceby running the following command:CREATE UNDO TABLESPACE tablespace_name DATAFILE 'datafile name' SIZE 32M REUSE AUTOEXTEND ON EXTENT MANAGEMENT LOCAL - Set the following
init.oraparameters:- undo_management = AUTO
- undo_tablespace = tablespace_name
- undo_retention = 900
...