Oracle GoldenGate Interview Questions & Answers
1. How can you see GoldenGate errors?
Answer :Yes We Can See the Goldengate Error by following these simple steps :
ggsci> VIEW GGSEVT
2.How do you take backup of GoldenGate?
Answer : The Backup Process for Oracle GoldenGate is basically performed by utilizing the working framework cp order. The reinforcement ought to incorporate the root index and sub-catalogs. The sub-indexes incorporate the boundary documents and other related records. Utilizing the â€”R choice recursively reinforcement the sub-indexes. (Oracle GoldenGate Interview Questions)
3. Distinguish between classical extract and integrated extract?
Answer : Classical Extract: The Classic Extract mode is the conventional Extract measure that gets to the information base re-try logs (alternatively document logs) to catch the DML changes happening on the articles indicated in the boundary records. There are some information types that are not upheld in Classic Capture mode. Classical Extract can’t peruse information from the packed tables/tablespaces. These Goldengate interview questions will be very helpful. You Can Enrol for our Goldengate Training which will help you to learn advanced concepts.
Integrated Extract: In the Integrated Extract mode, GoldenGate works straightforwardly with the information base log mining worker to get the information changes as intelligent change records (LCRs). IC mode doesn’t need any uncommon arrangement for the information bases utilizing ASM, straightforward information encryption, or Oracle RAC.
4. What type of Topology does Goldengate support?
Answer : The Topology supported by goldengate are Unidirectional, Bidirectional, Peer-to-peer , Broadcast , Consolidation , Cascading.
5. What is the data pump process in Goldengate?
Answer : The Data Pump is a discretionary optional Extract bunch that is made on the source framework. At the point when Data Pump isn’t utilized, the Extract cycle keeps in touch with a far off path that is situated on the objective framework utilizing TCP/IP. GoldenGate Interview Questions The benefits of this be it ensures against an organization disappointment as without a capacity gadget on the neighborhood framework, the Extract cycle composes information into memory before the equivalent is sent over the organization. Any disappointments in the organization could then reason the Extract cycle to prematurely end (abend). Likewise, in the event that we are doing any mind boggling information change or sifting, the equivalent can be performed by the Data Pump.
6.When making a GoldenGate info user for info 12c, what special precaution does one got to take?
Answer : You should permit the GoldenGate administrator shopper admittance to all or any info base holders on the supply aspect with the goal that GoldenGate will get to the re-try logsYou must additionally grant the DBA role with the container=all choice. ( oracle goldengate tutorial will level up your skills for better understanding the subject )
7.What is suplimental work and why it’s needed for gg replication?
Answer : About Suplimental Logging: Supplemental work as name suggests is further work, needed to unambiguously distinguishing a row on course info once a row is updated/deleted from supply info.once a row is updated / deleted from the supply, GoldenGate Replicat method searches for constant row on course supported column supplementally logged before the dealings may well be applied.Supplemental work Levels: GoldenGate Interview Questions there is 2 level of supplemental logging:Supplemental work is needed by every amendment knowledge Capture (CDC) tool.GoldenGate being government agency tool therefore it additionally needs supplemental work to be enabled so as that rows updated on supply area unit usually unambiguously known at Target and updated.
8.Where the filtering of information for a column cans will be configured?
Answer : Filtering of the columns of a table is commonly set at the Extract, Pump or Replicat level.Explore the journal post on Oracle GoldenGate coaching to become an expert in Oracle GoldenGate.Is it a demand to tack a PUMP extract method in Oracle GoldenGate replication?PUMP extract is associate degree choice, however it’s extremely counseled to use this to safeguard against network failures.unremarkably it’s organized once you’re fixing Oracle GoldenGate replication across the network.
9.How will we tend to confirm the parameters for a method was recently changed?
Answer : Whenever a method is started, the parameters inside the prm file for the tactic is written to the tactic REPORT.You’ll look into the older method reports to seem at the parameters that GoldenGate Interview Questions were accustomed begin the tactic.By comparison the older and so the present reports you may establish the changes inside the parameters.
10.How to list out the restore points in RMAN?
Answer : In RMAN you may use the LIST RESTORE purpose [ALL|restore_point_name] command.If you use a recovery catalog you may use the read RC_RESTORE_POINT inside the recovery catalog repository, or command the V$RESTORE_POINT inside the target info. GoldenGate Interview Questions Provided by SVR Technologies will help you to crack the interview
11.How Can I set the info to boost Flashback performance?
Answer : Here area unit a number of the issues you want to inspect it to boost Performance:Use a fast classification system for your flash recovery space, ideally while not OS file caching.it’s counseled to use a classification system that avoids OS file caching, like ASM.Configure enough disk spindles for the classification system which is able to hold the flash recovery space.for large GoldenGate Interview Questions production databases, multiple disk spindles may even be required to support the desired disk turnout for the info to write down down the flashback logs effectively.If the storage system accustomed hold the flash recovery space does not have non-volatile RAM, plan to tack the classification system on high of patterned storage volumes, with a relativelythis might permit every pen the flashback logs to be unfold across multiple spindles, rising performancefor large, production databases, set the init.ora parameter LOG_BUFFER to be a minimum of 8MB.This makes positive the info allocates most memory (typically 16MB) for writing flashback info logs. (GoldenGate Interview Questions)
12.What is ggsci?
Answer : Golden Gate instruction Interface essential commands – GGSCI
GGSCI — (Oracle) GoldenGate Software Command Interpreter
13.What are macros?
Answer : Macro is a neater thanks to build your parameter file. Once a macro is written it are often called from different parameter files. Common parameters like username/password and other parameters are often included in these macros.
14.How is a macro defined?
Answer : A macro statement consists of the following.
• Name of the Macro
• Parameter list
• Macro body
Frequently Asked GoldenGate Interview Questions
15.What are the different encryption levels in AES?
Answer : You can encrypt the password/data using the AES in three different keys as follows
• 128 bit
• 192 bit and
• 256 bit
16.What is the task of the DBWR method and the way several DBWR processes square measure there?
Answer : DBWR Means, info author is very answerable for writing changed blocks(ie.dirty blocks) to the physical knowledge files(disks).An excessive quantity of dirty buffers in Buffer cacheTable house being born (or)taken offline(or) placed in browse solely mode, (or) in hot backup mode.When the supply and so the target schema objects are not constant (different DDL) the Replicat GoldenGate Interview Questions method should grasp the supply definition of the objects.The output from the DEFGEN utility is utilized in conjunction with the path knowledge to figure out that column worth inside the path belongs to that column.(GoldenGate Interview Questions)
17.How is that the RESTARTCOLLISION parameter completely different from HANDLECOLLISIONS?
Answer : The RESTARTCOLLISION parameter is utilized to skip ONE dealing solely throughout a state of affairs once the Golden Gate method crashed associate degreed performed an operation (INSERT, UPDATE & DELETE)inside the info however could not stop the tactic data to the stop file/table.On recovery it’s going to skip the dealing and mechanically still later operation inside the GoldenGate Interview Questions path file.once victimization HANDLECOLLISIONS Golden Gate can still write and method transactions till the parameter is much far from the parameter files and so the processes restarted.
18.How will we have a tendency to report on long running transactions?
Answer : The WARNLONGTRANS parameter square measure typically mere with a threshold time that a dealing square measure typically open before Extract writes a warning message to the ggs error log (GoldenGate Interview Questions)
19.Why would you segregate the tables in an exceedingly replication configuration?
Answer : In OGG you may tack replicat at the data at the schema level or at the table level victimization TABLE parameter of extract and MAP parameter of replicat.For replicating the complete info you may list all the schemas inside the info inside the extract/replicat parameter file or else you may conjointly a collection of tables inside theAlternatively you may need to take away tables that have long running transactions throughout a separate extract method to eliminate lag on the alternative tables.Let’s say merely|that you just} simply have a schema named SCOTT and its a hundred hundred tables.Out of these hundred tables, fifty tables square measure heavily used by application.Oracle can decide to keep the utmost quantity Flashback logs PRN to satisfy the DB_FLASHBACK_RETENTION_TARGET parameter.However, if there’s house pressure inside the Flash Recovery space (FRA), flashback logs might even be deleted to create space for alternative things, like backups and archived logs.(Latest GoldenGate Interview Questions)
20.What is the distinction between Classic and Coordinated Replicat?
Answer : The distinction between classic mode and coordinated mode is that Replicat is multi-threaded in coordinated mode.inside one Replicated instance, multiple threads browse the path severally and apply transactions in parallel.every thread handles all of the filtering, mapping, conversion, SQL construction, and error handling for its allotted employment.
21.How to list restore points in RMAN?
Answer : In RMAN you may use the LIST RESTORE purpose [ALL|restore_point_name] command. If you utilize a recovery catalog you may use the read RC_RESTORE_POINT among the recovery GoldenGate Interview Questions catalog repository, or the command the V$RESTORE_POINT among the target info.
22.How will instance recovery add associate oracle database?
Answer : When associate instance terminated as abnormally or crashed the info goes down in associate inconsistent state which means all current transactions committed or uncommitted weren’t completed. therefore before it’s usually opened, the info should be throughout an even mode. thus SMON performs a important role in convalescent the info. Oracle uses the last SCN among the management file and may apply committed or uncommitted transactions from Redo logs, that is known as roll forward. throughout this state info is in MOUNT state. info then checks GoldenGate Interview Questions the accessibility of UNDO segments and opens the info. currently uncommitted transactions square measure rolled back with the help of UNDO, that is called ROLL BACK.
23.What is BATCHSQL mode ?
Answer : In BATCHSQL mode, Replicat organizes similar SQL statements into batches among a memory queue, then it applies everyte. GoldenGate process works supported Parameters defined in Parameter files. Every Process in GoldenGate has its own Parameter file. [GoldenGate Interview Questions ]
24.What is CDR in Golden Gate?
Answer : Oracle GoldenGate Conflict Detection associate degreed determination (CDR) provides basic conflict resolution routines that: Resolve a singularity conflict for an INSERT . Resolve a “no information found” conflict for associate degree UPDATE once the row exists, however the before image of one or additional columns is totally different from the current price at intervals the info.GoldenGate has addressed this issue through the use of the BATCHSQL configuration parameter for the Replicat method. BATCHSQL segregates similar SQL statements into batches and GoldenGate Interview Questions applies all of them directly. Similar SQL statements ar those that perform a specific operation sort (insert, update, or delete) against the same target table with the same column list.
25.Why does one ought to increase price of UNDO_RETENTION parameter whereas putting in place GoldenGate?
Answer : It is needed to increase the UNDO_RETENTION price so as that GoldenGate will maintain a read-consistent row image for a specific time or SCN to match the redo record. Please note that Oracle GoldenGate Interview Questions 12c uses Flashback question to urge all the values from the undo records. For special info objects like User-defined sorts, Nested tables etc. Increasing UNDO_RETENTION can ensure that GoldenGate is in a very position to satisfy the goal of scan consistency.(GoldenGate Interview Questions and answers)
26.Explain high level steps of GoldenGate ?
Answer : Below area unit the key steps to install/configure the GoldenGate system.
Download the package from the Oracle web site and transfer to server
Unpack/Unzip the installation nada file
Prepare supply and target system
Install the package on the supply and target system (for 12c use OUI)
Prepare the supply information (some decibel parameters ought to be adjusted) tack together the Manager method on the supply and target system
Configure the Extract method on the supply system
Configure the information pump method on the supply system
Configure the Replicat method on the target system
Start the Extract method
Start the information pump method
Start the Replicat method
27.How ought to I set the information to enhance Flashback performance?
Answer : Here square measure a number of the issues you need to investigate it to enhance Performance:
GoldenGate Interview Questions Use a fast classification system for your flash recovery space, ideally while not OS file caching. it’s counseled to use a classification system that avoids OS file caching, like ASM.
Configure enough disk spindles for the classification system which is able to hold the flash recovery space. for large production databases, multiple disk spindles might even be required to support the desired disk output for the information to write down down the flashback logs effectively.If the storage system accustomed hold the flash recovery space does not have non-volatile RAM, arrange to put together the classification system on high of patterned storage volumes, with a relatively.(GoldenGate Interview Questions 2020)
28.What is suplimental logging work and why it’s needed for gg replication?
Answer : About Suplimental Logging: Supplemental work as name suggests is further work, needed to unambiguously characteristic a row heading in the right direction info once a row is updated/deleted from supply info. once a row is updated / deleted from the supply, GoldenGate Replicat method searches for a similar row heading in the right direction supported column supplementally logged before the dealing may be applied.
Supplemental work Levels: there is 2 level of supplemental logging:
Supplemental work is needed by every modification knowledge Capture (CDC) tool. GoldenGate being federal agency tool therefore it additionally needs supplemental work to be enabled so as that rows updated on supply square measure usually unambiguously known at Target and updated. One of the reasons to modify supplemental work is to urge modification logs for the update and delete statements. Supplemental work makes positive that enough data is captured throughout this updates and deletes which can use by any methodology supported logminer technology. Since GoldenGate could also be a SQL Apply therefore once a row is updated or deleted from the supply, GoldenGate Replicat method searches for a similar row heading in the right direction on that update/delete should be performed. GoldenGate Interview Questions
29.List out some of the important considerations for bi-directional replication?
Answer : Here are some of the Important Considerations for bi-directional Replication mentioned below: The customer should consider the subsequent points in an active-active replication environment.
• Primary Key: Helps to spot conflicts and Resolve them.
• Sequences: aren’t supported. The work around is to use odd/even, range or concatenate sequences.
• Data Looping: this will easy avoided using OGG itself
• LAG: this could be minimized. If a customer says that there’ll not be any LAG thanks to network or huge load, then we don’t got to deploy CRDs. But this is often not the case always as there would be some LAG and these can cause Conflicts.
• CDR (Conflict Detection & Resolution): OGG has inbuilt CDRs for all types of DMLs which will be wont to detect and resolve them.
• Packaged Application: These aren’t supported because it may contain data types which aren’t supported by OGG or it’d not allow the appliance modification to figure with OGG
30.What is the purpose of the DEFGEN utility?
Answer : When the source and therefore the target schema objects aren’t an equivalent (different DDL) the Replicat process must know the source definition of the objects. The output from the DEFGEN utility is employed in conjunction with the trail data to work out which column value within the trail belongs to which column.The above mention GoldenGate Interview Questions will help you to ace from beginner level to an advanced level.