Interview Questions.

Question 1. Explain The Difference Between A Hot Backup And A Cold Backup And The Benefits Associated With Each.

Answer :

A warm backup is essentially taking a backup of the database even as it's far nonetheless up and strolling and it need to be in archive log mode. A bloodless backup is taking a backup of the database at the same time as it's far shut down and does now not require being in archive log mode. The gain of taking a warm backup is that the database is still to be had to be used while the backup is happening and you may get better the database to any point in time. The gain of taking a chilly backup is that it's miles generally less complicated to administer the backup and healing technique. In addition, because you are taking bloodless backups the database does not require being in archive log mode and for that reason there may be a moderate performance gain as the database isn't always slicing archive logs to disk.

Question 2. You Have Just Had To Restore From Backup And Do Not Have Any Control Files. How Would You Go About Bringing Up This Database?

Answer :

I would create a textual content primarily based backup control document, stipulating where on disk all of the records documents where and then difficulty the get better command with the using backup manage record clause.

Oracle 10g Interview Questions
Question three. How Do You Switch From An Init.Ora File To A Spfile?

Answer :

Issue the create spfile from pfile command.

Question 4. Explain The Difference Between A Data Block, An Extent And A Segment.

Answer :

A records block is the smallest unit of logical garage for a database object. As objects develop they take chunks of extra storage which are composed of contiguous information blocks. These groupings of contiguous statistics blocks are referred to as extents. All the extents that an object takes whilst grouped together are considered the phase of the database item. Extent won't be non-stop.

Oracle 10g Tutorial
Question five. Give Two Examples Of How You Might Determine The Structure Of The Table Dept.

Answer :

Use the describe command or use the dbms_metadata.Get_ddl package.

Oracle 8i Interview Questions
Question 6. Where Would You Look For Errors From The Database Engine?

Answer :

In the alert log.

Question 7. Compare And Contrast Truncate And Delete For A Table?

Answer :

Both the truncate and delete command have the preferred final results of having rid of all the rows in a table. The difference between the 2 is that the truncate command is a DDL operation and simply moves the high water mark and produces a now rollback. The delete command, however, is a DML operation, that allows you to produce a rollback and therefore take longer to finish.

Oracle 9i Tutorial Informatica Interview Questions
Question eight. Give The Reasoning Behind Using An Index?

Answer :

Faster get right of entry to to records blocks in a table.

Question 9. Give The Two Types Of Tables Involved In Producing A Star Schema And The Type Of Data They Hold.

Answer :

Fact tables and dimension tables. A truth desk carries measurements whilst size tables will contain facts with the intention to help describe the reality tables.

PL/SQL Interview Questions
Question 10. What Type Of Index Should You Use On A Fact Table?

Answer :

A Bitmap index.

Oracle 8i Tutorial
Question eleven. Give Two Examples Of Referential Integrity Constraints?

Answer :

A number one key and a foreign key.

Oracle 11g Interview Questions
Question 12. A Table Is Classified As A Parent Table And You Want To Drop And Re-create It. How Would You Do This Without Affecting The Children Tables?

Answer :

Disable the foreign key constraint to the determine, drop the table, re-create the desk, enable the foreign key constraint.

Oracle 10g Interview Questions
Question 13. Explain The Difference Between Archivelog Mode And Noarchivelog Mode And The Benefits And Disadvantages To Each?

Answer :

ARCHIVELOG mode is a method that you could positioned the database in for developing a backup of all transactions that have occurred within the database so that you can get better to any factor in time. NOARCHIVELOG mode is essentially the absence of ARCHIVELOG mode and has the drawback of now not being capable of get better to any factor in time. NOARCHIVELOG mode does have the gain of no longer having to put in writing transactions to an archive log and as a result increases the overall performance of the database slightly.

Informatica Tutorial
Question 14. What Command Would You Use To Create A Backup Control File?

Answer :

Alter database backup manipulate record to trace.

Question 15. Give The Stages Of Instance Startup To A Usable State Where Normal Users May Access It?

Answer :

STARTUP NOMOUNT – Instance startup. Control File is examine here.

STARTUP MOUNT – The database is set up. Datafiles are read for the status and checked with manipulate document.

STARTUP OPEN – The database is opened. Normal users can get entry to.

SQL Interview Questions
Question 16. What Column Differentiates The V$ Views To The Gv$ Views And How?

Answer :

The INST_ID column which indicates the instance in a RAC environment the facts came from.

Oracle 11g Tutorial
Question 17. How Would You Go About Generating An Explain Plan?

Answer :

Create a plan table with utlxplan.Square.
Use the explain plan set statement_id = ‘tst1’ into plan_table for a SQL declaration
Look at the give an explanation for plan with utlxplp.Square or utlxpls.Square

Oracle apps Interview Questions
Question 18. How Would You Go About Increasing The Buffer Cache Hit Ratio?

Answer :

Use the buffer cache advisory over a given workload after which question the v$db_cache_advice table. If a alternate turned into vital then I could use the regulate machine set db_cache_size command.

Oracle 8i Interview Questions
Question 19. Explain An Ora-01555

Answer :

You get this error when you get a picture too old inside rollback. It can normally be solved by increasing the undo retention or increasing the dimensions of rollbacks. You ought to also have a look at the common sense concerned in the application getting the error message.

Question 20. Explain The Difference Between $oracle_home And $oracle_base?

Answer :

ORACLE_BASE is the basis listing for oracle. ORACLE_HOME positioned under ORACLE_BASE is wherein the oracle products are living.

Sybase Interview Questions
Question 21. How Would You Determine The Time Zone Under Which A Database Was Operating?

Answer :

pick out DBTIMEZONE from dual;

Question 22. Explain The Use Of Setting Global_names Equal To True?

Answer :

Setting GLOBAL_NAMES dictates how you might connect to a database. This variable is both TRUE or FALSE and if it's miles set to TRUE it enforces database hyperlinks to have the identical call because the far flung database to which they may be linking.

Question 23. Explain The Difference Between A Function, Procedure And Package?

Answer :

A characteristic and system are the equal in that they're supposed to be a set of PL/SQL code that consists of a unmarried venture. While a process does now not should return any values to the calling software, a feature will return a single fee. A package deal on the other hand is a group of capabilities and methods which can be grouped collectively based on their commonality to a enterprise function or software.

Oracle Apps ERP Interview Questions
Question 24. Explain The Use Of Table Functions.

Answer :

Table capabilities are designed to return a set of rows through PL/SQL good judgment but are intended to be used as a everyday desk or view in a SQL assertion. They are also used to pipeline information in an ETL procedure.

Informatica Interview Questions
Question 25. Name Three Advisory Statistics You Can Collect.

Answer :

Buffer Cache Advice, Segment Level Statistics, & Timed Statistics.

Question 26. Where In The Oracle Directory Tree Structure Are Audit Traces Placed?

Answer :

In unix $ORACLE_HOME/rdbms/audit, in Windows the occasion viewer

Oracle 7.3 Interview Questions
Question 27. Explain Materialized Views And How They Are Used.

Answer :

Materialized views are gadgets that are reduced sets of facts which have been summarized, grouped, or aggregated from base tables. They are generally used in information warehouse or choice assist systems.

PL/SQL Interview Questions
Question 28. When A User Process Fails, What Background Process Cleans Up After It?

Answer :

PMON

Question 29. What Background Process Refreshes Materialized Views?

Answer :

The Job Queue Processes.

Oracle Access Manager Interview Questions
Question 30. What Is The Difference Between Oltp And Olap?

Answer :

OLTP is nothing however OnLine Transaction Processing ,which includes a normalised tables and on line data,that have common insert/updates/delete.

But OLAP(Online Analtical Programming) incorporates the history of OLTP statistics, that is, non-volatile ,acts as a Decisions Support System and is used for creating forecasting reports.

Question 31. How Would You Determine What Sessions Are Connected And What Resources They Are Waiting For?

Answer :

Use of V$SESSION and V$SESSION_WAIT

Question 32. Describe What Redo Logs Are?

Answer :

Redo logs are logical and bodily systems which can be designed to hold all of the adjustments made to a database and are intended to resource in the restoration of a database.

Oracle Application Framework Interview Questions
Question 33. How Would You Force A Log Switch?

Answer :

ALTER SYSTEM SWITCH LOGFILE;

Oracle 11g Interview Questions
Question 34. Give Two Methods You Could Use To Determine What Ddl Changes Have Been Made.

Answer :

You should use Logminer or Streams

Question 35. What Does Coalescing A Tablespace Do?

Answer :

Coalescing is most effective valid for dictionary-managed tablespaces and de-fragments area via combining neighboring free extents into massive single extents.

Question 36. What Is The Difference Between A Temporary Tablespace And A Permanent Tablespace?

Answer :

A brief tablespace is used for brief objects such as kind structures while everlasting tablespaces are used to save those gadgets supposed to be used as the proper items of the database.

SQL Interview Questions
Question 37. Name A Tablespace Automatically Created When You Create A Database?

Answer :

The SYSTEM tablespace.

Question 38. When Creating A User, What Permissions Must You Grant To Allow Them To Connect To The Database?

Answer :

Grant the CONNECT to the user.

Question 39. How Do You Add A Data File To A Tablespace?

Answer :

ALTER TABLESPACE <tablespace_name> ADD DATAFILE <datafile_name> SIZE <size>

Question forty. How Do You Resize A Data File?

Answer :

ALTER DATABASE DATAFILE <datafile_name> RESIZE <new_size>;

Oracle apps Interview Questions
Question forty one. What View Would You Use To Look At The Size Of A Data File?

Answer :

DBA_DATA_FILES

Question 42. What View Would You Use To Determine Free Space In A Tablespace?

Answer :

DBA_FREE_SPACE

Sybase Interview Questions
Question 43. How Would You Determine Who Has Added A Row To A Table?

Answer :

Turn on best grain auditing for the table.

Question 44. How Can You Rebuild An Index?

Answer :

ALTER INDEX <index_name> REBUILD;

Question forty five. Explain What Partitioning Is And What Its Benefit Is.

Answer :

Partitioning is a method of taking massive tables and indexes and splitting them into smaller, greater doable pieces.

Question forty six. You Have Just Compiled A Pl/sq. Package But Got Errors, How Would You View The Errors?

Answer :

SHOW ERRORS

Question forty seven. How Can You Gather Statistics On A Table?

Answer :

The ANALYZE command.

Question forty eight. How Can You Enable A Trace For A Session?

Answer :

Use the DBMS_SESSION.SET_SQL_TRACE or

Use ALTER SESSION SET SQL_TRACE = TRUE;

Question 49. What Is The Difference Between The Sql*loader And Import Utilities?

Answer :

These two Oracle utilities are used for loading statistics into the database. The difference is that the import utility is predicated at the statistics being produced with the aid of every other Oracle application EXPORT even as the SQL*Loader software permits facts to be loaded that has been produced via different utilities from exceptional facts assets simply so long because it conforms to ASCII formatted or delimited documents.

Question 50. Name Two Files Used For Network Connection To A Database.

Answer :

TNSNAMES.ORA and SQLNET.ORA