Oracle Data Guard interview questions

 

Showing posts with label Oracle DBA Interview questions. Show all posts

Friday, November 1, 2019

Oracle Data Guard interview questions

Oracle Data Guard interview questions

1.what is the differance between physical standby & logical standby?
2.what are the process involved in Physical standby?
3.what is active data guard?
4.what are the parameters that needed to set in DB level for physical standby?
5.what is the process used for data guard broker?
6.What is the use of standby redolog?
7.What are different protection modes in dataguard?
8.What is snapshot standby database?
9.What is the difference between switchover and failover?
10.What is the process to apply a psu patch in dataguard setup?
11.What is the use of  fal_client and fal_server parameter in dataguard environment?
12.What is standby_file_management parameter oracle?
13.few of the archives got deleted and  before applying to DG ,how to sync the DG with primary?
14.I added a tempfile on primary database, but the tempfile is not reflecting on standby database despite, the standby_file_management is set to AUTO,why?
15.What are the different types of redo transport services in dataguard.?
16.What are the different services available in Oracle Data Guard?
17.How to check what protection mode of primary database in your Oracle Data Guard?
18.What is the usage of DB_FILE_NAME_CONVERT parameter in Oracle Data Guard setup?
19.How to delay the application of logs to a physical standby?
20.How many standby databases we can create (in 10g/11g)?
21.What are differences between physical, logical, snapshot standby and ADG (or) what are different types of standby databases?
22.What are the parameters we’ve to set in primary/standby for Data Guard?
23.What is the use of fal_server & fal_client, is it mandatory to set these?
24.How to find out backlog of standby?
25.If you didn't have access to the standby database and you wanted to find out what error has occurred in a data guard configuration, what view would you check in the primary database to check the error message?
26.How can you recover standby which far behind from primary (or) without archive logs how can we make standby sync?
27.What are advantages offered by Maximum Performance protection mode?
28.What are the benefits of maximum protection mode?
29.How is the maximum protection mode enabled?
30.What are the advantages of maximum availability protection mode?
31.What is the utility of the Redo Transport Service?
32.What do you understand by Broker in this software?
33.What are the tasks that you can perform using Broker?
34.What are the disadvantages that are associated with the Logical Standby systems?
35. What Is Dg Broker?
36. What Is The Difference Between Data Guard And Standby?
37.What Are New Features In 11g Data Guard?
38.What Is the use of  Dg_config  parameter?
39.What Is Rta (real Time Apply) Mode Mrp?
40.What Is The Difference Between Sync/async, Lgwr/arch, And Affirm/noaffirm ?
41.What Is Staticconnectidentifier Property Used For?
42.Steps To Create Physical Standby Database?
43.what is Fast-Start Failover in DG?
44.Does DG broker needs separate licence?
45.what are the conditions Fast-Start Failover will initiate?
46.what is  Dataguard Broker Observer?
47.what is the use of NetTimeout parameter in DG?
48.how to find if real time apply enabled on DG?
49.which DG mode ,primary response will be good?
50.what will happen if standby down on max.protection mode?
51.what is the pre-request for Fast-Start Failover?
52.how to redirect data guard broker log into a file?
53.How to reinstate the old Primary as a Standby after Failover in Oracle DB?
54.what  is the view used to check that archive log applied to standby DB?
55.why do we need same password file used for DG setup?
56.how to stop archive shipping without stopping the DB?
57.how to recover/sync standby DB if primary object configured with nologging options?
58.how to move a datafile that created on primary but not created on standby ,even though standby_file=auto?
59.why do we need pwd file  need  while configuring the DG?
60.why standby db always has more redolog group than primary db?
61.when we configure the standby DB,will that standby DB in archive or no archive mode?
62.what are the steps to start the physical DB for real time apply mode?
63.can we open physical standby DB in read only mode?
64.can the init parameter change will reflect from primary to standby db?
65.How many MRP process would exist on the typical standby DB?
66.when the standby DB open what are the operations allowed?
67.There was a block corruption on Primary db  will that cause any problem on standby DB?
68.can you tell me paramater for 1 to many DG configuration ,cascading model?
69.can we cascade physical standby from RAC to another standby?
70.if we give access to DB how to find out physical standby configured or not for the database?
71.what are the pre-request for creating the snapshopt standby database?
72.what are the parameter change needed to configure RAC to standby configuration and NON RAC to standby configuration?
73.what are the various mehtod to cone/create the standby database from Primary  database?

Saturday, December 31, 2016

Oracle Database internal interview questions

Oracle Database internal interview questions
1.How the user session established in oracle database?
2.How the user fetching the data from data file in oracle DB?
3.what are sequence of activities happening during insert/update/delete in oracle DB?
4.how the data selection happening in oracle RAC DB?
5.what happen to uncommitted transactions on UNDO in oracle DB?
6.How Database & ASM communicates when you select query run on database?
7.How oracle applies redo changes to physical standby?
8.what is the sequence of steps to generate the archive log in oracle DB?
9.what will happen internal ,when you update the oracle database?
10.what are internal changes will happen,when you do switch over in physical standby?
11.How oracle RAC provides service availability when the nodes fail-over on one of the 2 node RAC?
12.how oracle internally allocates space to system object extension?
13.what will happen when you rebuild index online?
14.what will happen ,when you do re-balance on ASM DISK?
15.what will happen when you kill the flashback process in oracle database?
16.what is the   use of OS kernal parameter in oracle database server?
17.How to allocate memory for the database in oracle database?
18.can flashback database brings dropped datafile in database?
19,what is the object sequence for export/import in oracle database?
20.what will happen when you apply CPU & PSU on oracle home?
21.what is the startup sequence of oracle RAC database?
22.what will happen when you kill the archive process in oracle database?
23.How the user session established in oracle RAC database?
24.what will happen when you try to create object on ASM instance?
24.How do you backup ASM instance?
25.what is the use of begin backup mode in oracle hot backup?
26.will RMAN hot backup put the database to begin backup mode ?

Sunday, March 20, 2016

Senior Oracle DBA Goldengate interview questions

Oracle DBA Goldengate interview questions:

1.       What are the important process in GG?

2.       What is difference between CSN, SCN?

3.       What is extract, replicat?

4.       What are the GG types or topologies?

5.       How to get log from source & target?

6.       Difference between classic & integral extract process?

7.       What are the pre-request for GG?

8.       Types of replication in GG?

9.       What are the areas monitoring required in GG?

10.   What is the difference between local trail / Remote Trail?

11.   What are the GG utilities used?

12.   How to define size for extract file?

13.   How to change GG writing extract file?

14.   How to purge extract file automatically?

15.   How to check how many extract file created per day?

16.   What to check, when replication steps in primary & target?

17.   How to start/stop, extract/replicat for source & target?

18.   How to sync target with source if we missed the trail file?

19.   What is the format for trail file?

20.   What is the default location for the trail file & can we change the trail file location?

21.   What is the datapump in GG?

22.   Is there any limit in extract groups / Replicat numbers?

23.   What are the GG views?

24.   What is GLOBAL file in GG & location?

25.   What are the directory in GG?

26.   What is credential store?

27.   What are the types of encryption supported by GG?

28.   What is obey usage?

29.   What is discard file & usage? Can we change from default location?

30.   How to switch writing to new trail file?

31.   What is the proper steps to shutdown GG database?

32.   How to automatically remove old trail file?

33.   How to enable automatic for replicat/ extract?

34.   What are the parameter file used by GG?

35.   What are the limitation for bidirectional GG?

36.   What is the use of REPERROR in GG?

37.   How to check latency between source & GG?

38.   What is utility used to open trail file in GG?

39.   How to check particular trail file needed or not?

40.   What are the various GG operational types?

41.   What is reverse utility?

42.   In unidirectional GG setup, steps to add a table for replication?

43.   Can we change the GG oracle DB without setting up in operating system level?

44.   What are the types extract check point positions?

45.   How to change the trail file size in GG?

46.   How to check all records processed in replicat? Info replicat group , it should return <EOF>

47.   How to calculate & allocate swap space for GG server?

48.   How to check last 5 recent extract checkpoints?

49.   How to control the checkpoint in extract & replicat?

50.   How to confirm extract in working file in GG?

51.   What are the recovery types in extract process?

52.   How to setup lag process time in GG?

53.   How to manager process to check extract/replicat lag?

54.   How to view GG error log & process report?

55.   How to check how many records processed in replication /extraction?

56.   What is discard file? How to check default location?
57. How to check ,how many updates/deletes happened on GG in particular time?
58. what is archive log only mode in GG?
59. what is the command to see the recovery status in GG?
60.what is the use of SOURCEISTABLE &SPECIALRUN keyword in GG?

TOP oracle database administrator performance tuning interview questions

Senior  oracle DBA performance tuning interview questions

1.       How to take explain plan for table? Methods?

2.       How to check when the SQL executed in DB?

3.       How to check SQL is done hard or soft parse?

4.       How to compare the DB performance between two different timings?

5.       How to run the SQL Tunning advisor?

6.       How to Oracle base line for SQL?

7.       How to create SQL profile for sql addmprt?

8.       How to run addm and use?

9.       How to run awr and use?

10.   When to run ash and use for ashrpt.sql?

11.   Steps to run SQL Tunning advisor using OEM?

12.   Steps to check different hash value for SQL?

13.   How to check whether SQL is in cursor cache or not?

14.   Steps to run the segment advisor using OEM?

15.   Steps to run SQL Tunning advisor using OEM?

16.   Steps to create Oracle SQL profile using OEM?

17.   Steps to create ash report for particular OEM sql-id?

18.   Steps to compare two different timing awr using OEM?

19.   Steps to get historical SQL using OEM?

20.   How to force oracle to pick a index?

21.   Steps to check oracle execution plan using OEM?

22.   Steps to check how many times SQL executed and execution time using OEM?

23.   What is access advisor?

24.   What is adaptive cursor sharing?

Manual SQL Tunning:

1.       What are the list of areas to look into AWR for tunning?

2.       What are the areas we will look into ash report?

3.       When to collect stats for a table?

4.       When to rebuild index for a table?

5.       How do you say DB health is good?

6.       What are the areas you need to look when application says performance and what are the areas you will look into it?

7.       How to check top SQL from the database?

8.       How to check what are the objects accessed by a Query?

9.       Steps to run SQL tunning advisor manually?

10.   Steps to run SQL tunning using OEM?

11.   How to get bind values of SQL Query?

12.   What is SQL advisor?

13.   What is wait Events? How do you restore the issue?

14.   What is physical reads / logical reads? How do you restore the issue?

15.   What is high I/O? How do you restore the issue?

16.   When will you create baseline for SQL?

17.   Steps to force oracle use index?

18.   Cursor-sharing parameter effect on DB?

19.   What is the difference between explain plan & execution plan?

20.   How to change the SQL query to bad execution plan?

21.   Steps to restore optimizer statistics for a table?

22.   How to see stats retention periods and how to alter it?

23.   How to flush a particular object from shared pool?

24.   Steps to do export & import scheme stats?

25.   What is the stale stats? How to unlock the stats?

26.   What is the difference between lock and latch?

27.   How to check explain plan for already ran SQL?

28.   How to find out whether query run CBO & RBO?

29.   Parallel execution of SQL Query?

30.   Performance Tunning parameter?

31.   What is the areas to look into AWR?

32.   What are the areas to look into ASH?

33.   How many blocks used by an object?

34.   When to rebuild index? Run segment advisor, if we have defragmentation run it?

35.   When to collect stats for a table using SQL tunning advisor recommendation & ADDM?

36.   When the stats become state stats? 10% data change?

37.   How to find out current wait Events in DB?

38.  V$A-S-H, V$A-S-Wait, V$Session-wait

39.   How to fix sort-area-site? V$sysstat?

40.   Performance stated init parameters?

41.   How to check explain plan for already ran SQL?

42.   How to find whether query used CBO & RBO?

43.   Steps to check awr retention period? Snapshot time & how to change it?

44.   ASH retention period? Can we change?

45.   Compare AWR report by awrddrpt.sql?

46.   Are you aware of Awrgrpt.sql & AWR report?

47.   AWR vs ASH generation methods & types?

48.   Scripts to check wait Events? 

49.   What are the different methods of tracing session?