Oracle Applications Idle Session Timeout

What is Session Idle time?

If Oracle Apps client is idle for some time (Eg. Application user goes for a coffee break) session during that time is called as Idle Session & because of security reason, performance issues and to free up system resource Oracle Applications terminates client session (both forms & self service) after idle time value is reached to the one mentioned in configuration file.

To enter into application, profile option "ICX Session Timeout" is used.

ICX Session Time out mentioned in profile option ICX: Session Timeout is in minutes, so ICX session timeout=30 

From where ICX: Session Timeout & session.timeout get values?

Autoconfig determines value for profile option "ICX: Session Timeout" and "session.timeout" from entry in context file ($APPL_TOP/admin/SID_hostname.xml) with parameter s_sesstimeout where value mentioned is in milliseconds so profile option ICX: Session Timeout value should be s_sesstimeout/ (1000 * 60) which means here its 10 Minutes. This value is also set in zone.properties in $IAS_ORACLE_HOME/Apache/Jserv where number mentioned is in milli second i.e. 600000 (equal to 10 Minutes) session.timeout = 600000.

Eg.  Session Timeout is in minutes, so ICX session timeout=480 is 8Hrs. 

Difference Between Oracle apps 11i & R12

Summary of Changes :

Component	Release 11i	Release 12
Database	9.2	10.2
Developer	6i	10i
Application Server	1.0	10.1
Client Plug-in	Jinitiator	SUN JRE
Java Containers	Jserv	OC4J

Changes in Detail :

APPMGR
	OLD	NEW
APPL_TOP	$HOME/<SID>appl	$HOME/apps/apps_st/appl
COMMON_TOP	$HOME/<SID>comn	$HOME/apps/apps_st/comn
ORACLE_HOME	$HOME/<SID>ora/8.0.6	$HOME/apps/tech_st/10.1.2
IAS_ORACLE_HOME	$HOME/<SID>ora/iAS	$HOME/apps/tech_st/10.1.3
ORACLE
	OLD	NEW
ORACLE_HOME	$HOME/<SID>db/10.2.0	$HOME/db/tech_st/10.2.0
ORADATA	$HOME/<SID>data	$HOME/db/apps_st/data
INST_TOP (New Addition)
	OLD	NEW
INST_TOP	NA	$HOME/inst/apps/<context_name>

What’s new in Oracle Apps R12

Key points to Note:

1. Oracle Applications Release 12 is the latest release in the chain of E-Business Suite Releases by Oracle.
2. This release came up with the new file system model
3. Autoconfig will not write anything in APPL_TOP, COMMON_TOP area in R12.
4. All instance specific configurations, log files are written in INST_TOP area. This home provides the ability to share Applications and technology stack.

R12 new features

1. Applications Server 9i is replaced by 10g (10.1.3.X)
2. Forms & Reports Version 6i (8.0.6) are replaced by Forms & Reports Version 10g i.e. 10.1.2.X
3. mod_jserv is replaced by oc4j
4. Java/ JDK version 1.3.X or 1.4.X will be replaced by JDK 1.5.X

Techstack Components Changes

• Database (RDBMS_ORACLE_HOME) - 10.2.0.2
• FORMS ORACLE_HOME (8.0.6 ORACLE HOME equivalence) - 10.1.2
• OC4J_ORACLE_HOME (iAS ORACLE_HOME equivalence) - 10.1.3

File system level changes

• A new top INSTANCE_TOP is introduced in Release 12 for configuration and log files along with the other TOP's in existing in 11i.
• All instance specific configurations, log files are written in INST_TOP area. 
• This home provides the ability to share Applications and technology stack.

What is INSTANCE TOP 

• Instance home is the top-level directory for an applications instance which is known as Instance Home and is denoted the environment variable $INST_TOP. 
• This contains all the config files, log files, SSL certificates etc.

Advantages of new INSTANCE HOME

• The additional Instance Home makes the middle tier easier to manage and organized since the data is kept separate from the config files.
• The Instance Home also has the ability to share the Applications and Technology stack code across multiple instances.
• Another advantage of the Instance Home is that the autoconfig writes only in INST_TOP so APPL_TOP and ORACLE_HOME can also be made read only file system if required.

Oracle Exadata Interview Questions

1. What are the different Exadata configurations?
The Exadata Appliance configuration comes as a Full Rack, Half Rack or Quarter Rack.

The Full Rack X2-2 has 6 CPUs per node with Intel Xeon 5670 processors and a total of 8 Database Server nodes, also known as compute nodes.These servers have 96GB of memory on each node. A total of 14 Storage server cells communicate with the storage and push the requested data from the storage to the compute nodes.

The Half Rack has exactly half the capacity. It has 6 CPUs per node with core Intel Xeon 5670 processors and a total of 4 Database Server nodes. It has 96GB of memory per database server node with a total of 7 Storage server cells

2. What are the key Oracle Exadata Features?
Some of the key hardware and software features are:

Hardware level
• Storage Server Cells
• High Speed Infiniband Switch

Software level
• Smart Scan,
• Flash Cache
• Hybrid Columnar Compression
• IORM (I/O Resource Manager)

3. What is a Cell and Grid Disk?
Cell and Grid Disk are a logical component of the physical Exadata storage. A cell or Exadata Storage server cell is a combination of Disk Drives put together to store user data. Each Cell Disk corresponds to a LUN (Logical Unit) which has been formatted by the Exadata Storage Server Software. Typically, each cell has 12 disk drives mapped to it.

Grid Disks are created on top of Cell Disks and are presented to Oracle ASM as ASM disks. Space is allocated in chunks from the outer tracks of the Cell disk and moving inwards. One can have multiple Grid Disks per Cell disk.

4. What is IORM?
IORM stands for I/O Resource Manager. It manages the I/O demand based on the configuration, with the amount of resources available. It ensures that none of the I/O cells become oversubscribed with the I/O requests. This is achieved by managing the incoming requests at a consumer group level. Using IORM, you can divide the I/O bandwidth between multiple databases. To implement IORM resource groups, consumers and plans need to e created.

5. What is hybrid columnar compression?
Hybrid Columnar compression, also called HCC, is a feature of Exadata which is used for compressing data at column level for a table. It creates compression data units which consist of logical grouping of columns values typically having several data blocks in it. Each data block has data from columns for multiple rows. This logarithm has the potential to reduce the storage used by the data and reduce disk I/O enhancing performance for the queries.
6. What is Flash cache?

Four 96G PCIe flash memory cards are present on each Exadata Storage Server cell which provide very fast access to the data stored on it. This reduces data acess latency by retrieving data from memory rather than having to access data from disk. A total flash storage of 384GB per cell is available on the Exadata appliance.

7. What is Smart Scan?

8. What are the Parallelisim instance parameter used in Exadata?
The parameter PARALLEL_FORCE_LOCAL can be specified at the session level for a particular job.

9. What are the ways to migrate onto Exadata?
Depending on the downtime allowed there are several options:
• Traditional Export/Import
• Oracle DataGuard
• Tablespace transportation.
• Goldengate Replication after a data restore onto Exadata.