Interview Questions.

Question 1. What Type Of Topology Does Goldenggate Support?

Answer :

GoldenGate supports the subsequent topologies:

Unidirectional
Bidirectional
Peer-to-peer
Broadcast
Consolidation
Cascasding
Question 2. What Are The Main Components Of The Goldengate Replication?

Answer :

The replication configuration consists of the following strategies:

Manager
Extract
Pump
Replicate
Oracle 10g Interview Questions
Question 3. What Transaction Types Does Goldengate Support For Replication?

Answer :

Goldengate helps each DML and DDL Replication from the source to target.

Question 4. What Are The Supplemental Logging Pre-specifications?

Answer :

The following supplemental logging is required.

Database supplemental logging
Object degree logging
Oracle 10g Tutorial
Question five. Why Is Supplemental Logging Required For Replication?

Answer :

Integrated Capture (IC):

In the Integrated Capture mode, GoldenGate works without delay with the database log mining server to obtain the statistics modifications in the form of logical trade information (LCRs).
IC mode does not require any special setup for the databases using ASM, transparent statistics encryption, or Oracle RAC.
This characteristic is most effective to be had for oracle databases in Version eleven.2.0.3 or better.
It additionally helps diverse object kinds which had been previously now not supported through Classic Capture.
This Capture mode helps extracting information from source databases the usage of compression.
Integrated Capture can be configured in an online or downstream mode.
Oracle 9i Interview Questions
Question 6. List The Minimum Parameters That Can Be Used To Create The Extract Process?

Answer :

The following are the minimal required parameters which ought to be defined inside the extract parameter file.

EXTRACT NAME
USERID
EXTTRAIL
TABLE
Question 7. I Want To Configure Multiple Extracts To Write To The Same Exttrail File? Is This Possible?

Answer :

Only one Extract procedure can write to one exttrail at a time. So you could’t configure more than one extracts to put in writing to the equal exttrail.

Oracle 9i Tutorial Oracle 8i Interview Questions
Question 8. What Type Of Encryption Is Supported In Goldengate?

Answer :

Oracle Goldengate offers three types of Encryption.

Data Encryption using Blow fish.
Password Encryption.
Network Encryption.
Question 9. What Are The Different Password Encryption Options Available With Ogg?

Answer :

You can encrypt a password in OGG the usage of

Blowfish set of rules and
Advance Encryption Standard (AES) set of rules
Informatica Interview Questions
Question 10. What Are The Different Encryption Levels In Aes?

Answer :

You can encrypt the password/statistics using the AES in 3 different keys

128 bit
192 bit and
256 bit
Oracle 8i Tutorial
Question 11. What Are Some Of The Key Features Of Goldengate 12c?

Answer :

The following are some of the greater interesting features of Oracle GoldenGate 12c:

Support for Multitenant Database
Coordinated Replicat
Integrated Replicat Mode
Use of Credential store
Use of Wallet and master key
Trigger-much less DDL replication
Automatically adjusts threads when RAC node failure/start
Supports RAC PDML Distributed transaction
RMAN Support for mined archive logs
PL/SQL Interview Questions
Question 12. What Are The Installation Options Available In Ogg 12c?

Answer :

You can set up Oracle GoldenGate 12c the use of in 2 ways:

Interactive Installation with OUI – Graphical interface
Silent Installation with OUI – Command Interface
Oracle 10g Interview Questions
Question thirteen. What Is A Credential Store In Ogg 12c?

Answer :

OGG Credential Store manages Encrypted Passwords and USERIDs which are used to interact with the neighborhood database and Associate them with an Alias. Instead of specifying actual USERID and Password in a command or a parameter report, you can use an alias. The Credential Store is applied as an car login wallet in the Oracle Credential Store Framework (CSF).

Informatica Tutorial
Question 14. How To Configure Credential Store In Ogg 12c?

Answer :

Steps to configure Oracle Credential Store are as follows:

By Default Credential Store is is placed beneath “dircrd” directory.
If you need to specify a unique area use can specidy “CREDENTIALSTORELOCATION” parameter in GLOBALS file.
Example: CREDENTIALSTORELOCATION /u01/app/oracle/OGG_PASSWD

Goto OGG home and hook up with GGSCI.
Cd $OGG_HOME
./ggsci
GGSCI>

Question 15. What Command Is Used To Create The Credential Store?

Answer :

ADD CREDENTIALSTORE.

Oracle 11g Interview Questions
Question sixteen. How Do You Add Credentials To The Credential Store?

Answer :

ALTER CREDENTIALSTORE ADD USER userid,
[PASSWORD password]
[ALIAS alias]
[DOMAIN domain]
Example: GGSCI> ALTER CREDENTIALSTORE ADD USER GGS@orcl, PASSWORD oracle ALIAS extorcl DOMAIN OracleGoldenGate

Oracle 11g Tutorial
Question 17. How Do You Retrieve Information From The Oracle Credential Store?

Answer :

GGSCI> INFO CREDENTIALSTORE
OR
GGSCI> INFO CREDENTIALSTORE DOMAIN OracleGoldenGate

SQL Interview Questions
Question 18. What Are The Different Data Encryption Methods Available In Ogg 12c?

Answer :

In OGG 12c you may encrypt facts with the subsequent 2 strategies:

Encrypt Data with Master Key and Wallet
Encrypt Data with ENCKEYS
Oracle 9i Interview Questions
Question 19. How Do You Enable Oracle Goldengate For Oracle Database 11.2.0.4?

Answer :

The database services required to support Oracle GoldenGate capture and apply should be enabled explicitly for an Oracle eleven.2.Zero.Four database. This is required for all modes of Extract and Replicat.

To allow Oracle GoldenGate, set the subsequent database initialization parameter. All instances in Oracle RAC need to have the equal setting.

ENABLE_GOLDENGATE_REPLICATION=genuine

Question 20. How Does The Replicat Works In A Coordinated Mode?

Answer :

In a Coordinated Mode Replicat operates as follows:

Reads the Oracle GoldenGate trail.
Performs statistics filtering, mapping, and conversion.
Constructs SQL statements that constitute supply database DML or DDL transactions (in devoted order).
Applies the SQL to the target through the SQL interface that is supported for the given target database, including ODBC or the native database interface.
Oracle apps Interview Questions
Question 21. What Is The Difference Between Classic And Coordinated Replicat?

Answer :

The distinction between traditional mode and coordinated mode is that Replicat is multi-threaded in coordinated mode. Within a single Replicat instance, more than one threads read the trail independently and follow transactions in parallel. Each thread handles all of the filtering, mapping, conversion, SQL creation, and mistakes coping with for its assigned workload. A coordinator thread coordinates the transactions across threads to account for dependencies the various threads.

Question 22. How Do You Create A Coordinated Replicate In Ogg 12c?

Answer :

You can create the COORDINATED REPLICATE with the following OGG Command:

ADD REPLICAT rfin, COORDINATED MAXTHREADS 50, EXTTRAIL dirdat/et

Question 23. If Have Created A Replicate Process In Ogg 12c And Forgot To Specify Discardfile Parameter. What Will Happen?

Answer :

Starting with OGG 12c, if you don’t specify a DISCARDFILE OGG method now generates a dicard document with default values each time a process is started out with START command through GGSCI.

Sybase Interview Questions
Question 24. Is It Possible To Start Ogg Extract At A Specific Csn?

Answer :

Yes, Starting with OGG 12c you could now begin Extract at a selected CSN in the transaction log or trail.

Example:

START EXTRACT fin ATCSN 12345
START EXTRACT finance AFTERCSN 67890
Oracle 8i Interview Questions
Question 25. List A Few Parameters Which May Help Improve The Replicat Performance?

Answer :

The parameters under can be used to enhance the replicat performance:

BATCHSQL
GROUPTRANSOPS
INSERTAPPEND
Question 26. What Are The Areas To Monitor In Goldengate Replication?

Answer :

The lag and checkpoint latency of the Extract, pump and Replicat methods are generally monitored.

Oracle Apps ERP Interview Questions
Question 27. What Is The Passthru Mode Used For?

Answer :

In skip-via mode, the Extract procedure does not look up the table definitions, both from the database or from a information definitions record. This will increase the throughput of the facts pump, as the item definition appearance-up is bypassed.

Informatica Interview Questions
Question 28. What Are The Most Common Reasons Of An Extract Process Slowing Down?

Answer :

Some of the viable motives are:

Long going for walks batch transactions on a desk.
Insufficient reminiscence on the Extract facet. Uncommitted, lengthy jogging transactions can motive writing of a transaction to a transient area (dirtmp) on disk. Once the transaction is dedicated it is examine from the brief region on the report gadget and converted to trail files.
Slow or overburdened Network.
Question 29. What Are The Most Common Reasons Of The Replicate Process Slowing Down?

Answer :

Some of the possible motives are:

Large quantity of transactions on a selected table.
Blocking sessions on the vacation spot database where non-Goldengate transactions are also taking area at the same table because the replicat processing.
If the usage of DBFS, writing & reading of path documents can be sluggish if SGA parameters aren't tuned.
For sluggish Replicat’s, latency may be due to lacking indexes heading in the right direction.
Replicat having to manner Update, delete of rows in very huge tables.
Oracle 7.3 Interview Questions
Question 30. My Extract Was Running Fine For A Long Time. All Of A Sudden It Went Down. I Started The Extract Processes After 1 Hour. What Will Happen To My Committed Transactions That Occurred In The Database During Last 1 Hour?

Answer :

OGG checkpoint affords the fault tolerance and make certain that the transaction marked for devoted is capture and captured most effective as soon as. Even if the extract went down abnormally, while you start the method once more it reads the checkpoint report to provide the examine consistency and transaction recuperation.

Question 31. I Have Configured Oracle Goldengate Integrated Capture Process Using The Default Values. As The Data Load Increases I See That Extract Starts Lagging Behind By An Hour (or More) And Database Performance Degrades. How You Will Resolve This Performance Issue?

Answer :

When operating in included capture mode, you have to make sure that you have assigned sufficient reminiscence to STREAMS_POOL_SIZE. An undersized STREAMS_POOL_SIZE or proscribing the streams pool to use a particular amount of memory can motive issues.

The great practice is to allocate STREAMS_POOL_SIZE at the instance level and allocate the MAX. SGA at GG procedure stage as under:

SQL> regulate system set STREAMS_POOL_SIZE=3G

TRANLOGOPTIONS INTEGRATEDPARAMS (MAX_SGA_SIZE 2048, PARALLELISM 4)

Question 32. Why Would You Segregate The Tables In A Replication Configuration? How Would You Do It?

Answer :

In OGG you could configure replicat on the information at the schema stage or at the desk stage the use of TABLE parameter of extract and MAP parameter of replicat.
For replicating the entire database you could listing all the schemas inside the database within the extract/replicat parameter document.
Depending the amount of redo generation you could break up the tables in a schema in a couple of extracts and replicats to enhance the performance of data replication. Alternatively youcan additionally institution a set of tables inside the confiuration via the software functionality.
Alternatively you can need to put off tables that have long running transactions in a seperate extract manner to eliminte lag on the alternative tables.
Let’s say that you have a schema named SCOTT and it has one hundred hundred tables.
Out of these hundred tables, 50 tables are closely utilized by application.

To improve the overall replication overall performance you create three extract and 3 replicats as follows:
Ext_1/Rep_1 –> 25 tables
Ext_2/Rep_2 –> 25 tables
Ext_3/Rep_3 –> 50 tables
Ext_1/Rep_1 and Ext_2/Rep_2 carries 25 table every that are closely applied or generate more redo.
Ext_3/Rep_3 includes all the different 50 tables that are least used.

Oracle Access Manager Interview Questions
Question 33. How Can We Report On Long Running Transactions?

Answer :

The WARNLONGTRANS parameter can be distinct with a threshold time that a transaction can be open before Extract writes a caution message to the ggs error log.

Example: WARNLONGTRANS 1h, CHECKINTERVAL 10m

PL/SQL Interview Questions
Question 34. What Command Can Be Used To View The Checkpoint Information For The Extract Process?

Answer :

Use the subsequent command to view the Extract checkpoint records.

GGSCI> info extract , showch

GGSCI> data extract ext_fin, showch

Question 35. How Is The Restartcollision Parameter Different From Handlecollisions?

Answer :

The RESTARTCOLLISION parameter is used to pass ONE transaction simplest in a scenario whilst the GoldenGate system crashed and achieved an operation (INSERT, UPDATE & DELETE) inside the database however could not checkpoint the manner statistics to the checkpoint record/desk. On restoration it'll skip the transaction and AUTOMATICALLY preserve to the following operation inside the path file.

When the usage of HANDLECOLLISION GoldenGate will continue to overwritten and technique transactions till the parameter is removed from the parameter documents and the processes restarted.

Question 36. How Do You View The Data Which Has Been Extracted From The Redo Logs?

Answer :

The logdump application is used to open the trail files and take a look at the actual data which have been extracted from the redo or the archive log files.

Oracle 11g Interview Questions
Question 37. What Does The Rman-08147 Warning Signify When Your Environment Has A Goldengate Capture Processes Configured?

Answer :

This occurs when the V$ARCHIVED_LOG.NEXT_CHANGE# is more than the SCN required by using the GoldenGate Capture manner and RMAN is attempting to delete the archived logs. The RMAN-08147 error is raised when RMAN attempts to delete these files.

When the database is open it uses the DBA_CAPTURE values to decide the log files required for mining. However if the database is within the mount state the V$ARCHIVED_LOG. NEXT_CHANGE# cost is used.

Question 38. How Would You Look At A Trail File Using Logdump, If The Trail File Is Encrypted?

Answer :

You should use the DECRYPT option before viewing statistics in the Trail statistics.
List few beneficial Logdump commands to view and search statistics stored in OGG trail documents.
Below are few logdump commands used on a every day basis for displaying or analyzing statistics saved in a path document.
$ ./logdump – to connect with the logdump set off
logdump> open /u01/app/oracle/dirdat/et000001 – to open a path file in logdump
logdump> fileheader on – to view the path file header
logdump> ghdr on – to view the report header with facts
logdump> detail on – to view column records
logdump> detail records – to show HEX and ASCII facts values to the column listing
logdump> reclen 2 hundred – to control how tons report data is displayed
logdump> pos 0 – To go to the first document
logdump> next (or truly n) – to transport from one document to any other in series
logdump> be counted – counting records in a path

Question 39. Why Should I Upgrade My Goldengate Extract Processes To Integrated Extract?

Answer :

Oracle is capable of provide quicker integration of the brand new database capabilities by way of shifting the GoldenGate Extraction procedures into the database. Due to this, the GoldenGate Integrated Extract has some of capabilities like Compression which are not supported inside the traditional Extract. You can read extra about how to improve to Integrated Extract and greater approximately Integrated Delivery. Going ahead desire must be give to create new extracts as Integrated Extracts and additionally to upgrade present conventional Extracts.

Question 40. What Is The Minimum Database Version Which Supports Integrated Delivery?

Answer :

Oracle 11.2.0.Four is the the minimal required database version which supports both Integrated extract and Integrated Reaplicat.

SQL Interview Questions
Question 41. What Databases Supports Goldengate Integrated Delivery?

Answer :

Oracle Integrated Delivery is handiest to be had for Oracle Databases.

Question 42. With Integrated Delivery, Where Can We Look For The Performance Stats?

Answer :

Yes with 12c, performance information are accumulated inside the AWR repository and the information is available via the everyday AWR reviews.

Oracle apps Interview Questions
Question forty three. What Are The Steps Required To Add A New Table To An Existing Replication Setup?

Answer :

The steps to be accomplished would be the following:

Include the new desk to the Extract & pump method.
Obtain starting database SCN and Copy the supply table data to the target database
Start Replicat on target at the supply SCN database point.
Question 44. What Does The Goldengate Csn Equate To, In The Oracle Database?

Answer :

It is equivalent of the Oracle database SCN transaction quantity.

Question 45. How Do You Create A Csv File From The Extracted Data?

Answer :

You will need to use the CSV Flat File Adaptor to create CSV files. The supply would be the extract trail documents which use the configuration of the adaptor settings to generate CSV files.

Question 46. What Is The Purpose Of The Defgen Utility?

Answer :

When the source and the goal schema objects are not the identical (different DDL’s) the Replicat system desires to realize the supply definition of the items. The output from the DEFGEN software is used along side the trail records to decide which column value inside the path belongs to which column.

Question 47. What Are The Basic Resources Required To Configure Oracle Goldengate High Availability Solution With Oracle Clusterware?

Answer :

There are three primary resources required:

Virtual IP
Shared storage
Action script
Question forty eight. I Have A One-manner Replication Setup. The System Administration Team Wants To Apply An Os Patch To Both The Ogg Source Host And The Target Servers. Provide The Sequence Of Steps That You Will Carry Before And After Applying This Patch?

Answer :

Procedure:

Check to ensure that the Extract has processed all the information in the information supply (Online Redo/archive logs)
GGSCI> send extract , logend
(The above command ought to print YES)

Verify the extract, pump and replicat has zero lag.
GGSCI> send extract , getlag
GGSCI> send extract , getlag
GGSCI> send replicat , getlag

(The above command ought to pring “At EOF, no greater statistics to process.”)

Stop all software and database activity.
Make sure that the number one extract is reading the give up of the redolog and that there is no LAG at all for the strategies.
Now continue with preventing the processes:
Source:

Stop the primary extract
Stop the pump extract
Stop the supervisor manner
Make certain all the strategies are down.
Target:

Stop replicat system
Stop mgr
Make positive that every one the methods are down.
Proceed with the maintenance
After the renovation, proceed with commencing the strategies:
Source:

Start the manager manner
Start the primary extract
Start the pump extract
(Or honestly all of the extract strategies as GGSCI> begin extract *)

Make positive all that the tactics are up.
Target:

Start the manager method
Start the replicat manner.
Make certain that each one the techniques are up.
Question 49. What Parameters Can Be Used To Configure Oracle Goldengate To Extract Data From Archived Redo Log Files Only?

Answer :

Use the TRANLOGOPTIONS ARCHIVEDLOGONLY alternative in the parameter report.

Question 50. What Is The Best Practice To Delete The Extract Files In Ogg?

Answer :

Use the supervisor procedure to delete the extract files after they may be fed on by the extract/replicat manner

PURGEOLDEXTRACTS /u01/app/oracle/dirdat/et*, USECHECKPOINTS, MINKEEPHOURS 2

Question fifty one. I Have A Table Called ‘take a look at’ On Source And Target With Same Name, Structure And Data Type But In A Different Column Order. How Can You Setup Replication For This Table?

Answer :

OGG by way of default assumes that the sources and target tables are same. A desk is stated to be same if and handiest if the table structure, records type and column order are the identical on both the source and the goal.

If the tables aren't equal you should use the parameter ‘SOURCEDEFS’ pointing to the supply desk definition and ‘COLMAP’ parameter to map the columns from supply to goal.

Question 52. What Are The Different Ogg Initial Load Methods Available?

Answer :

OGG has 2 functionalities, one it is used for Online information Replication and second for Initial Loading.

If you're replicating statistics among 2 homogeneous databases then the quality approach is to use database particular technique (Exp/Imp, RMAN, Transportable tablespaces, Physical Standby and so on). Database unique strategies are typically faster than the opposite methods.

—If you're replicating statistics among 2 heterogeneous databases or your replicat involves complicated ameliorations, then the database particular method can’t be used. In those cases you may constantly use Oracle GoldenGate to perform preliminary load.

Within Oracle GoldenGate you've got 4 special ways to carry out initial load.

Direct Load – Faster however doesn’t support LOB statistics sorts (12c consist of guide for LOB)
Direct Bulk Load – Uses SQL*LOAD API for Oracle and SSIS for MS SQL SERVER
File to replicat – Fast however the rmtfile restrict is 2GB. If the desk can’t be in shape in 1 rmtfile you can use maxfiles however the replicat need to be registered at the target OGG home to read the rmtfiles from supply.
File to Database utility – relying on the target database, use SQL*LOAD for Oracle and SSIS for MS SQL SERVER and so forth.
Oracle GoldenGate initial loading reads data directly from the supply database tables without locking them. So you don’t want downtime however it's going to use database assets and can cause overall performance issues. Take more precaution to perform the preliminary load for the duration of the non-height time so that you don’t run into aid rivalry.

Question fifty three. I Am Migrating My Oracle Database From Non-exadata To Exadata But My Source Ogg Software And Target Ogg Software Versions Are Different (say Source Is Running Ogg 11.1 And Target Is Running Ogg 11.2). How Can I Configure My Ogg Process To Work In Such Configuration?

Answer :

It is suggested that each one times of Oracle GoldenGate be the equal version to take advantage of the new functionality, but this isn't always possible all of the time and is not required. In this state of affairs, OGG offers a parameter referred to as ‘FORMAT RELEASE’ which permits clients to use one-of-a-kind versions of Oracle GoldenGate Extract, path documents, and Replicat together.

Example: RmtTrail /u01/app/oracle/dirdat, Format Release 11.1

Note: The enter and output trails of a statistics pump should have the equal path document version.

Question fifty four. We Want To Setup One-manner Data Replication For My Online Transaction Processing Application. However There Are Compressed Tables In The Environment. Please Suggest How I Can Achieve It?

Answer :

You should use OGG 11.2 and configure GoldenGate Integrated Capture system to extract statistics from compressed tables.

Note: Pre OGG eleven.2 doesn’t assist extracting information from compressed tables