Tips To Clear Oracle Exadata Certification Exam

Many DMA positions are available when you look for Oracle Exadata jobs, but it requires some skills to meet the job requirement. Credential of Oracle exadata certification is most appropriate for these position which can give confidence to the employer that you have a necessary skill to land for a job.

Oracle Exadata Certification is considered to be a one way ticket to a mouth-watering career in the field of Oracle Exadata Administrator, consultant and Implementer.

Today there are huge demand for Oracle Exadata Specialist in various industries. Also you can say DMA job is recession proof job in Oracle Database Technology.

Oracle offers two types of Exadata certifications. 

umount: /u01 device is busy

Recently we faced this error while un-mounting /u01 file system.

You can get this error in two case either some one is logged in into the file system or some process is using this file system.

We have checked that no one is using /u01 file system now only one option was there , some process is using /u01 file system which is not allowing us to un-mount it.

We can check with below command that which processes are associated with /u01 file system.

How to disable/enable CPUs in Linux ?

It's quite interesting to know how to disable and enable CPU core in Linux in different scenario.

Thought came from Exadata architecture as Exadata 1/8th Rack comes with 16 cores but only half of the CPUs will be enabled on the DB server, that's why we have to pay Oracle licence cost for half core only.

This enabling and disabling can be controlled by resource control utility which comes with Exadata, so what we can do to enable or disable cpu core in non Exadata server?

We have performed this test on test server which has four CPU cores.

Step 1: Check Total Available CPU

There are multiple method to check it, we have checked it with TOP utility which give you better understanding. It shows 4 cpu cores are available.

What is HARD in Oracle Exadata?

Hardware Assisted Resilient Data (HARD)

• HARD will prevent data corruptions from being written to storage disks.
• Oracle database validates and add protection while sending data to the storage server.
• Whenever data will go to storage server , first it will check if there is any data corruption. If it found the corrupted data , it would stops corrupted data from being written to disk.
• Previously or in non-Exadata hardware it's not possible to prevent corrupted data to be written on to the storage and that was major reason for database corruption in many cases which Oracle has eliminated with the use of storage software which has been introduced in Exadata storage cell.
• There is nothing to set on Database level or storage level as  HARD handle corruption transparently which also included for ASM rebalance.

Script to Find Hidden Parameters in Oracle

SELECT
  x.ksppinm name,
  y.ksppstvl VALUE,
  decode(ksppity,
    1,   'BOOLEAN',
    2,   'STRING',
    3,   'INTEGER',
    4,   'PARAMETER FILE',
    5,   'RESERVED',
    6,   'BIG INTEGER',
    'UNKNOWN') typ,

Exadata Dictionary Views

Listed down some Exadata views which can help you to get Exadata related statistics

Get Cell Definition

V$CELL 

GV$CELL 

Exadata cell effectiveness and statistics

V$SYSSTAT 

V$SEGMENT_STATISTICS 

V$SQL 

Historical view of the types and frequencies of the requests being run by a cell.

V$CELL_REQUEST_TOTALS 

Cell Performance Statistics

V$CELL_STATE 

Display Exadata Cell Threads

V$CELL_THREAD_HISTORY

Backup Related View

V$BACKUP_DATAFILE 

Password Aging in Linux

Disable Password Aging

#chage -M 99999 user_name

To get password expiration information

#chage -l user_name

To change aging

# chage -M 60 -m 7 -W 7 user_name

Here,

Minimum_days (M): The minimum number of days required between password changes i.e. the number of days left before the user is allowed to change his/her password.

Maximum_days(m): The maximum number of days the password is valid (after that user is forced to change his/her password).

Warn (W) : The number of days before password is to expire that user is warned that his/her password must be changed.

Oracle Exadata vs SAP HANA

We have provided some major difference between SAP HANA and Oracle Exadata. 

Even Exadata is not comparable with HANA than also we have tried to conclude it based on materials and documentation available in the market.

Oracle Exadata	SAP HANA
SAP HANA is an in-Memory Appliance.	SAP HANA is an in-Memory Appliance.
Oracle Exadata is based on Oracle servers, storage, networking, and software– all engineered and optimized to work together. It’s meant for Mixed workloads, i.e OLTP,DW	SAP HANA and partner solutions powered by the SAP HANA in-memory software. There are only a limited number of specialized SAP applications that run on HANA
We can use existing Oracle licences with Exadata	If we move to HANA, it's required to buy new licences as existing licences would not be reused
Oracle Exadata is delivered pre-configured, pre-tested and pre-optimized, with all necessary software, storage, hardware,and interconnect to lower total cost of ownership and provide quick time to value. Oracle Exadata is sold, delivered, and supported as a single-vendor solution with quick time-to-resolution.	SAP HANA relies on third-party compute, network,and storage vendors. Multiple points of support lead to longer downtimes and higher total cost of ownership. No single vendor is accountable for the solution's service-level agreements and due to its complexity, HANA deployments typically require a significant amount of effort.
Exadata can be used for any type of workload for any application which is running with Oracle Database	HANA is limited to SAP BW only. It doesn't support any other application
Exadata is capable for all type of workload so customer can consolidate multiple database on single machine.	SAP HANA runs only single application. It doesn't support multiple workload as well non sap DBs
Exadata comes with built in security	HANA don't have any encryption, auditing , compliance monitoring or any security certification
Oracle Exadata is enough smart to use RAM, Flash and Storage	HANA puts everything on memory
Exadata is single vendor optimized machine	HANA comes as an assemble hardware
Exadata is pre configured with HA and single point of hardware failure	HANA has limited capabilities in backup and recovery area. Also there is no failover solution as well disaster recovery solution
We can use IORM and instance caging in Exadata to prioritize the I/Os.	There is no features available to prioritize I/O in HANA
TCO is less compare to HANA	TCO is high compare to Exadata
Only Exadata DBA is required to manage Exadata	Multiple resource required to manage HANA

You can follow our Exadata Certification Question Bank to achieve maximum success in your Exadata certification.

Data Migration using Oracle Transportable Tablespace

Procedure to restore or migrate tablespace with the use of transportable tablespace.

There are two ways to moving tablespace/data to target system.

• Same platform data migration - Move data to same OS or endian, big to big endian or little to little endian operating system
• Cross platform data migration - Move data from little to big endian or big to little endian

If we are moving tablespace from little to big endian or big to little endian than we have to convert it to target endian platform which has been showed here in step-7.

If we are moving data to same endian platform operating system even to different OS than it's not required to use convert option.

List of operating system with endian format.

PLATFORM_ID	PLATFORM_NAME	ENDIAN_FORMAT
1	Solaris[tm] OE (32-bit)	Big
2	Solaris[tm] OE (64-bit)	Big
3	HP-UX (64-bit)	Big
4	HP-UX IA (64-bit)	Big
5	HP Tru64 UNIX	Little
6	AIX-Based Systems (64-bit)	Big
7	Microsoft Windows IA (32-bit)	Little
8	Microsoft Windows IA (64-bit)	Little
9	IBM zSeries Based Linux	Big
10	Linux IA (32-bit)	Little
11	Linux IA (64-bit)	Little
12	Microsoft Windows 64-bit for AMD	Little
13	Linux 64-bit for AMD	Little
14	HP Open VMS	Little
15	Apple Mac OS	Big

Now let's see the demo to migrate tablespace. Here we have created "ttest" tablespace to show the demo.