Technical points of concern for Oracle (RAC) database optimization and Accident Analysis

The Oracle Audit (Audit) function is used to monitor database operations performed by users. Audit records can be stored in data dictionary tables (called Audit records: SY stored in the system tablespace ).

The Oracle Audit (Audit) function is used to monitor database operations performed by users. Audit records can be stored in data dictionary tables (called Audit records: SY stored in the system tablespace ).

Oracle 11g Audit

The Oracle Audit (Audit) function is used to monitor database operations performed by users. Audit records can be stored in data dictionary tables (called Audit records: SYS. in the AUD $ table, view dba_audit_trail)

Or operating system audit records (default location: $ ORACLE_BASE/admin/$ ORACLE_SID/adump.

Regardless of whether or not the database audit function is enabled, the following Oracle operating systems will forcibly record:

Note: Audit is disabled for Oracle 10 Gb by default, while audit is enabled for Oracle 11g by default! Generally, the audit function is required for the core data of listed companies.

When audit data/logs are full, Oracle RAC cannot be used! Therefore, Oracle 11g should focus on the audit function, and close it if not necessary.

Oracle 10g ASM

In a massive database environment, DBA may spend a lot of time Managing disks. For example, if a tablespace occupies the entire disk, DBA needs to add another disk to the operating system, and then create a new data file on the new disk. If it is a single disk, this is not very cumbersome. The problem is that if we used RAID or LVM, a large amount of data is still distributed on those disks, if we want to evenly distribute the data on the previous disk and the Newly Added Disk, it may take a day or even a few days to export and import the original data.

If there is one way, we can add a disk to the system, and then tell Oracle that we want to use this disk. The rest of the work is done by Oracle, what a wonderful thing!

Oracle10g has provided this function, which is Automatic Storage Management (ASM ). Oracle10g ASM not only helps DBAs free from tedious disk space management, but also deserves more attention that ASM provides both strip and image functions, these functions were originally implemented by configuring RAID separately.

ASM provides the vertical integration function of the file system and volume manager dedicated for Oracle database files. ASM distributes I/O loads across all available resources to optimize performance while eliminating the need for manual I/O adjustment (avoiding hot spots by dispersing database files. ASM helps DBAs manage the dynamic database environment so that DBAs can adjust the storage allocation without shutting down the database while expanding the database scale.

ASM allows DBA to define a storage group (called a disk group ). Then, the Oracle kernel manages the names of files in the memory group and the placement of database files. DBAs can use the new SQL commands (create diskgroup, alter diskgroup, and drop diskgroup) to change storage allocation-add or delete disks. You can also use Enterprise Manager (EM) and database configuration Assistant (DBCA) to manage disk groups.

ASM promotes non-invasive storage configuration changes through automatic rebalancing. It allocates database files in all available memories to optimize performance and resource utilization.

ASM is a capability that saves DBA time by automating manual memory so that it can manage more and more databases with higher efficiency.

Make sure that your ASM function is correctly configured and enabled.