Monday, November 21, 2011

DBA and APPS DBA advanced interview questions

1)what is FNDLOAD?(APPS DBA interview)
(OR)
How we can migrate concurrent programs of one application?(Apps DBA)

Ans:FNDLOAD is a an Oracle utility to migrate data from one instance to another.It can be used with several different
entities within Oracle 11i,R12 applications.

Usage: FNDLOAD logon 0 Y mode configfile datafile [ entity [ param ... ] ]

where:
logon is username/password[@connect]
mode is either UPLOAD or DOWNLOAD
configfile is the configuration file
datafile is the data file
entity is an entity name, or - to specify all values in an upload
param is a NAME=VALUE string used for parameter substitution


FNDLOAD can be used for lot of migration/transfering task across Oracle Applications.They are

1)FNDLOAD can be used to transfer Request Groups
2)FNDLOAD can be used for moving Concurrent Programs.
3)FNDLOAD can be used to download and upload forms personalizations.
4)FNDLOAD can be used to migrate Key FlexFields, Descriptive Flexfields, Responsibilities and
almost every other FND entity

Eg:

##To FNDLOAD Concurrent Programs
FNDLOAD apps/$CLIENT_APPS_PWD O Y DOWNLOAD $FND_TOP/patch/115/import/afcpprog.lct
XX_CUSTOM_ORACLE_INTERFACE_PROG.ldt PROGRAM APPLICATION_SHORT_NAME="XXGMS"
CONCURRENT_PROGRAM_NAME="XX_CUSTOM_ORACLE_INTERFACE_PROG"


2)what is SCAN with respect to RAC?(DBA interview)

Ans: Single Client Access Name (SCAN) is s a new Oracle Real Application Clusters (RAC) 11g Release 2 feature that provides
a single name for clients to access Oracle Databases running in a cluster. The benefit is that the client’s connect information does not need to change if you add or remove nodes in the cluster. Having a single name to access the cluster allows clients to use the EZConnect client and the simple JDBC thin URL to access any database running in the cluster, independently of which server(s) in the cluster the database is active. SCAN provides load balancing and failover for client connections to the database. The SCAN works as a cluster alias for databases in the cluster.

There are 2 options for defining the SCAN:
1. Define the SCAN in your corporate DNS (Domain Name Service)
2. Use the Grid Naming Service (GNS)

In case, a 2-node-cluster is used (for which 3 IPs are still recommended for simplification reasons), one server in the cluster will host two sets of SCAN resources under normal operations. If the node where a SCAN VIP is running fails,
the SCAN VIP and its associated listener will failover to another node in the cluster. If by means of such a failure the number of available servers in the cluster becomes less than three, one server would again host two sets of SCAN
resources. If a node becomes available in the cluster again, the formerly mentioned dispersion will take effect and
relocate one set accordingly.

Configuring SCAN:

#srvctl config scan_listener
#srvctl config scan

For Oracle Database 11g Release 2, SCAN is an essential part of the configuration and therefore the
REMOTE_LISTENER parameter is set to the SCAN per default, assuming that the database is created using standard Oracle tools (e.g. the formerly mentioned DBCA).This allows the instances to register with the SCAN Listeners as remote listeners to provide information on what services are being provided by the instance, the current load, and a recommendation on how many incoming connections should be directed to the instance.
In this context, the LOCAL_LISTENER parameter must be considered. The LOCAL_LISTENER parameter should
be set to the node-VIP.

Eg:

local_listener=>(DESCRIPTION=(ADDRESS_LIST=(AD
DRESS=(PROTOCOL=TCP)(HOST=133.
22.67.111)(PORT=1521))))
remote_listener=>sales1-scan.example.com:1521

Note: ThE example Oracle 11g Release 2 client using a default TNSNAMES. ora will be as follows:

ORCLservice =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST=sales1-scan.example.com)(PORT=1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME =MYORCLservice)
))


3)How in R12 Jinitiator is placed?(APPS DBA interview)

Ans:
In App 11i, in context file we see s_sun_plugin_type set to jinit

Where as,In App R12 it is set to jdk

In Context.xml file we will find the line as given below in Apps R12

1.6.0_07
jdk


4)What are the background process in Dataguard physical standby setup and Logical standby setup?(DBA interview)
Ans: In additional to Mandatory Oracle background processes,the background processes playing key role in Dataguard physical standby and Logical Standby Setup are:

1)ARC0 Archiver Process on Local Server
2)ARCH Archiver
3)ASYNC Asynchronous
4)DMON Data Guard Monitor
5)FAL Fetch Archive Log =>For Pysical Standby setup
6)LCR Logical Change Record =>For Logical Standby setup
7)LGWR Logwriter
8)LNS Network Server Process
9)LSP Logical Standby Process (SQL Apply for Logical DG)=>For Logical Standby setup
10)MRP Managed Recovery Process (Redo Apply for Physical DG)=>For Pysical Standby setup
11)RFS Remote File Server
12)SYNC Synchronous

5)Which background process is responsible for recovery processes in physical standby database?(DBA interview)
Ans: MRP(Managed recovery process) is responsible for recovery process in physical standby Database in a Dataguard Configuration.

6)which background process is responsible for recovery in logical standby database?(DBA interview)
Ans:LSP(Logical standby process) is responsible for recovery in logical standby database in a Dataguard configuration.


7)What we should do if when applying patch the adpatch utility fails and Now you want to use adadmin/adpatch utility again? (Apps DBA)
Ans: Both AD utilities (adpatch/adadmin) access the same tables to store the workers details, so both FND_INSTALL_PROCESSES and AD_DEFERRED_JOBS tables need to be dropped from the failed adpatch session ,so that adadmin/adpatch session can run successfully next time.


Happy Interviews

Best regards,

Rafi

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