Archive for the ‘oracle’ Category
Tuesday, January 22nd, 2008
I/O stack components Overview
Typically the stack consists of the following
• Database
• Character or block device driver
• Multipathing driver
• SCSI driver
• HBA
• System Bus
• Switch/iSCSI routers
• Storage Array
• Disks
Example of vendors:
ASM-Database IBM Oracle
Character or block device driver
Multipathing driver – PowerPath, Windows MPIO
SCSI driver
HBA – Host Bus Adapter, Qlogic (IBM), Emulex
System Bus ...
Posted in hardware setup, oracle, ibm db2, Back-of-the-Envelope, Database, Storage, Design, Fibre Channel, Capacity planning | No Comments »
Tuesday, January 22nd, 2008
Don't forget to add extra IO imposed by users of the database. For example, to determine how much extra I/O will be imposed on the system when the new load is put into place. For example, if more users or reports will be added, determine how much I/O these reports ...
Posted in oracle, Back-of-the-Envelope, Storage, Design, Capacity planning | No Comments »
Tuesday, January 22nd, 2008
IO rate of 1+ Gigabytes/sec is rarely achievable, but hundreds of Megabytes/sec is achieved in lots of high-end production environment. Keep those numbers in mind when planning for what's possible.
In Oracle, use AWR reports to determine current I/O metrics (Instance Activity Stats per sec).
• IOPS = “physical reads total I/O ...
Posted in oracle, Back-of-the-Envelope, Database, Design, Capacity planning | No Comments »
Tuesday, January 22nd, 2008
IOPS
• The standard unit of measurement for I/O operations per second.
Includes all reads and writes.
• This is how you rate a I/O stack components ability to process small
block random I/O requests.
• Used to describe I/O rate driven applications (OLTP, random I/O )
Mbytes/s
• Mega”Bytes” per sec
• Used to measure large block ...
Posted in oracle, Back-of-the-Envelope, Database, Storage, Design | No Comments »
Thursday, June 14th, 2007
This tip resolves Oracle client error: "ORA-12705: Cannot access NLS data files or invalid environment specified". According to Oracle documentation, "ORA-12705" can happen under the following conditions:
1. ORA-12705 with incorrect NLS_LANG parameter
2. ORA-12705 with incorrectly specified ORA_NLSx
3. ORA-12705 from incorrect Oracle install or configuration
4. ORA-12705 when using Special Character ...
Posted in oracle | No Comments »
Tuesday, June 5th, 2007
Below shows simple steps in Oracle 9i and 10g to backup and restore Oracle databases; the goal is for the tasks to be called remotely so they can be automated as part of a performance test execution (i.e., always restores a known baseline before start a test!)1) Shuts down the ...
Posted in automation, backup and restore, windows, oracle | No Comments »