DBA Professional focused Interview Questions-Answers:

DBA Professional focused Interview Questions-Answers:

1. Explain the difference between a hot backup and a cold backup and the benefits associated with each.?

A hot backup is basically taking a backup of the database while it is still up and running and it must be in archive log mode. A cold backup is taking a backup of the database while it is shut down and does not require being in archive log mode. The benefit of taking a hot backup is that the database is still available for use while the backup is occurring and you can recover the database to any point in time. The benefit of taking a cold backup is that it is typically easier to administer the backup and recovery process. In addition, since you are taking cold backups the database does not require being in archive log mode and thus there will be a slight performance gain as the database is not cutting archive logs to disk.

 

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?

I would create a text based backup control file, stipulating where on disk all the data files where and then issue the recover command with the using backup control file clause.

3. How do you switch from an init.ora file to a spfile?

Issue the create spfile from pfile command.

 

4. Explain the difference between a data block, an extent and a segment.?

A data block is the smallest unit of logical storage for a database object. As objects grow they take chunks of additional storage that are composed of contiguous data blocks. These groupings of contiguous data blocks are called extents. All the extents that an object takes when grouped together are considered the segment of the database object.

5. Give two examples of how you might determine the structure of the table DEPT.?

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

 6. Where would you look for errors from the database engine?

 In the alert log.

 7. Compare and contrast TRUNCATE and DELETE for a table.?

Both the truncate and delete command have the desired outcome of getting rid of all the rows in a table. The difference between the two is that the truncate command is a DDL operation and just moves the high water mark and produces a now rollback. The delete command, on the other hand, is a DML operation, which will produce a rollback and thus take longer to complete.

8. Give the reasoning behind using an index.?

Faster access to data blocks in a table.

9. Give the two types of tables involved in producing a star schema and the type of data they hold.?

Fact tables and dimension tables. A fact table contains measurements while dimension tables will contain data that will help describe the fact tables.

10. What type of index should you use on a fact table?

A Bitmap index.

11. Give two examples of referential integrity constraints.?

A primary key and a foreign key.

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?

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

 

13. Explain the difference between ARCHIVELOG mode and NOARCHIVELOG mode and the benefits and disadvantages to each.?

ARCHIVELOG mode is a mode that you can put the database in for creating a backup of all transactions that have occurred in the database so that you can recover to any point in time. NOARCHIVELOG mode is basically the absence of ARCHIVELOG mode and has the disadvantage of not being able to recover to any point in time. NOARCHIVELOG mode does have the advantage of not having to write transactions to an archive log and thus increases the performance of the database slightly.

 

14. What command would you use to create a backup control file?

Alter database backup control file to trace.

15. Give the stages of instance startup to a usable state where normal users may access it.?

STARTUP NOMOUNT - Instance startup

STARTUP MOUNT - The database is mounted

STARTUP OPEN - The database is opened

16. What column differentiates the V$ views to the GV$ views and how?

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

17. How would you go about generating an EXPLAIN plan?

Create a plan table with utlxplan.sql.

Use the explain plan set statement_id = 'tst1' into plan_table for a SQL statement

Look at the explain plan with utlxplp.sql or utlxpls.sql

18. How would you go about increasing the buffer cache hit ratio?

Use the buffer cache advisory over a given workload and then query the v$db_cache_advice table. If a change was necessary then I would use the alter system set db_cache_size command.

19. Explain an ORA-01555

You get this error when you get a snapshot too old within rollback. It can usually be solved by increasing the undo retention or increasing the size of rollbacks. You should also look at the logic involved in the application getting the error message.

20. Explain the difference between $ORACLE_HOME and $ORACLE_BASE.?

 

ORACLE_BASE is the root directory for oracle. ORACLE_HOME located beneath ORACLE_BASE is where the oracle products reside.

21. How would you determine the time zone under which a database was operating?

select DBTIMEZONE from dual;

  

22. Explain the use of setting GLOBAL_NAMES equal to TRUE.

Setting GLOBAL_NAMES dictates how you might connect to a database. This variable is either TRUE or FALSE and if it is set to TRUE it enforces database links to have the same name as the remote database to which they are linking.

23. What command would you use to encrypt a PL/SQL application?

WRAP

24. Explain the difference between a FUNCTION, PROCEDURE and PACKAGE.?

A function and procedure are the same in that they are intended to be a collection of PL/SQL code that carries a single task. While a procedure does not have to return any values to the calling application, a function will return a single value. A package on the other hand is a collection of functions and procedures that are grouped together based on their commonality to a business function or application.

25. Explain the use of table functions.?

Table functions are designed to return a set of rows through PL/SQL logic but are intended to be used as a normal table or view in a SQL statement. They are also used to pipeline information in an ETL process.

26. Name three advisory statistics you can collect.?

Buffer Cache Advice, Segment Level Statistics, & Timed Statistics

27. Where in the Oracle directory tree structure are audit traces placed?

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

  

28. Explain materialized views and how they are used.?

Materialized views are objects that are reduced sets of information that have been summarized, grouped, or aggregated from base tables. They are typically used in data warehouse or decision support systems.

29. When a user process fails, what background process cleans up after it?

PMON

  

30. What background process refreshes materialized views?

The Job Queue Processes.

  

31. How would you determine what sessions are connected and what resources they are waiting for?

Use of V$SESSION and V$SESSION_WAIT

 32. Describe what redo logs are.?

Redo logs are logical and physical structures that are designed to hold all the changes made to a database and are intended to aid in the recovery of a database.

33. How would you force a log switch?

ALTER SYSTEM SWITCH LOGFILE;

34. Give two methods you could use to determine what DDL changes have been made.?

You could use Logminer or Streams

35. What does coalescing a tablespace do?

Coalescing is only valid for dictionary-managed tablespaces and de-fragments space by combining neighboring free extents into large single extents.

36. What is the difference between a TEMPORARY tablespace and a PERMANENT tablespace?

A temporary tablespace is used for temporary objects such as sort structures while permanent tablespaces are used to store those objects meant to be used as the true objects of the database.

37. Name a tablespace automatically created when you create a database.?

The SYSTEM tablespace.

  

38. When creating a user, what permissions must you grant to allow them to connect to the database?

Grant the CONNECT to the user.

  

39. How do you add a data file to a tablespace?

ALTER TABLESPACE ADD DATAFILE SIZE

  

40. How do you resize a data file?

ALTER DATABASE DATAFILE RESIZE ;

41. What view would you use to look at the size of a data file?

DBA_DATA_FILES

  

42. What view would you use to determine free space in a tablespace?

DBA_FREE_SPACE

43. How would you determine who has added a row to a table?

Turn on fine grain auditing for the table.

44. How can you rebuild an index?

ALTER INDEX REBUILD;

45. Explain what partitioning is and what its benefit is.?

Partitioning is a method of taking large tables and indexes and splitting them into smaller, more manageable pieces.

46. You have just compiled a PL/SQL package but got errors, how would you view the errors?

SHOW ERRORS

47. How can you gather statistics on a table?

The ANALYZE command.

48. How can you enable a trace for a session?

Use the DBMS_SESSION.SET_SQL_TRACE or

Use ALTER SESSION SET SQL_TRACE = TRUE;

  

49. What is the difference between the SQL*Loader and IMPORT utilities?

These two Oracle utilities are used for loading data into the database. The difference is that the import utility relies on the data being produced by another Oracle utility EXPORT while the SQL*Loader utility allows data to be loaded that has been produced by other utilities from different data sources just so long as it conforms to ASCII formatted or delimited files.

  

50. Name two files used for network connection to a database.?

TNSNAMES.ORA and SQLNET.ORA

                Data Base Administration

  

51. What is a database instance? Explain.

A database instance (Server) is a set of memory structure and background processes that access a set of database files. The processes can be shared by all of the users.

The memory structure that is used to store the most queried data from database. This helps up to improve database performance by decreasing the amount of I/O performed against data file.

52. What is Parallel Server?

Multiple instances accessing the same database (only in multi-CPU environments)

53. What is a schema?

The set of objects owned by user account is called the schema.

54.  What is an index? How it is implemented in Oracle database?

An index is a database structure used by the server to have direct access of a row in a table. An index is automatically created when a unique of primary key constraint clause is specified in create table command

55. What are clusters?

Group of tables physically stored together because they share common columns and are often used together is called cluster.

  

56. What is a cluster key?

The related columns of the tables are called the cluster key.  The cluster key is indexed using a cluster index and its value is stored only once for multiple tables in the cluster.

  

57. What are the basic element of base configuration of an Oracle database?

It consists of one or more data files.

one or more control files.

two or more redo log files.

The Database contains multiple users/schemas

one or more rollback segments

one or more tablespaces

Data dictionary tables

User objects (table,indexes,views etc.,)

The server that access the database consists of

SGA (Database buffer, Dictionary Cache Buffers, Redo log buffers, Shared SQL pool)

SMON (System MONito)

PMON (Process MONitor)

LGWR (LoG  Write)

DBWR (Data Base Write)

ARCH (ARCHiver)

CKPT  (Check Point)

RECO

Dispatcher

User Process with associated PGS

  

58. What is a deadlock? Explain.

Two processes waiting to update the rows of a table, which are locked by other processes then deadlock arises.

In a database environment this will often happen because of not issuing the proper row lock commands. Poor design of front-end application may cause this situation and the performance of server will reduce drastically.

These locks will be released automatically when a commit/rollback operation performed or any one of this processes being killed externally.

                 Memory Management  

59. What is SGA?

The System Global Area in an Oracle database is the area in memory to facilitate the transfer of information between users. It holds the most recently requested structural information between users. It holds the most recently requested structural information about the database. The structure is database buffers, dictionary cache, redo log buffer and shared pool area.

60. What is a shared pool?

The data dictionary cache is stored in an area in SGA called the shared pool. This will allow sharing of parsed SQL statements among concurrent users.

61. What is mean by Program Global Area (PGA)?

It is area in memory that is used by a single Oracle user process.

62. What is a data segment?

Data segment are the physical areas within a database block in which the data associated with tables and clusters are stored.

63. What are the factors causing the reparsing of SQL statements in SGA?

Due to insufficient shared pool size.

Monitor the ratio of the reloads takes place while executing SQL statements. If the ratio is greater than 1 then increase the SHARED_POOL_SIZE.

          Database Logical & Physical Architecture

64. What is Database Buffers?

Database buffers are cache in the SGA used to hold the data blocks that are read from the data segments in the database such as tables, indexes and clusters DB_BLOCK_BUFFERS parameter in INIT.ORA decides the size.

65. What is dictionary cache?

Dictionary cache is information about the database objects stored in a data dictionary table.

66. What is meant by recursive hints?

Number of times processes repeatedly query the dictionary table is called recursive hints. It is due to the data dictionary cache is too small. By increasing the SHARED_POOL_SIZE parameter we can optimize the size of data dictionary cache.

  

67. What is redo log buffer?

Changes made to the records are written to the on-line redo log files. So that they can be used in roll forward operations during database recoveries. Before writing them into the redo log files, they will first brought to redo log buffers in SGA and LGWR will write into files frequently. LOG_BUFFER parameter will decide the size.

68. How will you swap objects into a different table space for an existing database?

Export the user

Perform import using the command imp system/manager file=export.dmp indexfile=newrite.sql. This will create all definitions into newfile.sql.

Drop necessary objects.

Run the script newfile.sql after altering the tablespaces.

Import from the backup for the necessary objects.

69. List the Optional Flexible Architecture (OFA) of Oracle database?  How can we organize the tablespaces in Oracle database to have maximum performance?

SYSTEM - Data dictionary tables.

DATA  - Standard operational tables.

DATA2- Static tables used for standard operations

INDEXES - Indexes for Standard operational tables.

INDEXES1 - Indexes of static tables used for standard operations.

TOOLS - Tools table.

TOOLS1 - Indexes for tools table.

RBS - Standard Operations Rollback Segments,

RBS1,RBS2 - Additional/Special Rollback segments.

TEMP - Temporary purpose tablespace

TEMP_USER - Temporary tablespace for users.

USERS - User tablespace.

  

70. How will you force database to use particular rollback segment?

SET TRANSACTION USE ROLLBACK SEGMENT rbs_name.

71. What is meant by free extent?

A free extent is a collection of continuous free blocks in tablespace. When a segment is dropped its extents are reallocated and are marked as free.

  

72.Which parameter in Storage clause will reduce number of rows per block?

 PCTFREE parameter

 Row size also reduces no of rows per block.

73. What is the significance of having storage clause?

We can plan the storage for a table as how much initial extents are required, how much can be extended next, how much % should leave free for managing row updating, etc.,

  

74. How does Space allocation table place within a block?

Each block contains entries as follows

Fixed block header

Variable block header

Row Header, row date (multiple rows may exists)

PCTEREE (% of free space for row updating in future)

  

75. What is the role of PCTFREE parameter is storage clause?

This is used to reserve certain amount of space in a block for expansion of rows.

76. What is the OPTIMAL parameter?

 It is used to set the optimal length of a rollback segment.

77. What is the functionality of SYSTEM table space?

To manage the database level transactions such as modifications of the data dictionary table that record information about the free space usage.

78. How will you create multiple rollback segments in a database?

Create a database, which implicitly creates a SYSTEM rollback segment in a SYSTEM tablespace.

Create a second rollback segment name R0 in the SYSTEM tablespace.

Make new rollback segment available (after shutdown, modify init.ora file and start database)

Create other tablespaces (RBS) for rollback segments.

Deactivate rollback segment R0 and activate the newly created rollback segments.

79. How the space utilization takes place within rollback segments?

It will try to fit the transaction in a cyclic fashion to all existing extents. Once it found an extent is in use then it forced to acquire a new extent (number of extents is based on the optimal size)

80. Why query fails sometimes?

Rollback segment dynamically extent to handle larger transactions entry loads.

A single transaction may wipeout all available free space in the rollback segment tablespace. This prevents other user using rollback segments.

81. How will you monitor the space allocation?

 By querying DBA_SEGMENT table/view

  

82. How will you monitor rollback segment status?

Querying the DBA_ROLLBACK_SEGS view

IN USE          - Rollback Segment is on-line.

AVAILABLE    - Rollback Segment available but not on-line.

OFF-LINE- Rollback Segment off-line

INVALID - Rollback Segment Dropped.

NEEDS RECOVERY  - Contains data but need recovery or corrupted.

PARTLY AVAILABLE  - Contains data from an unresolved transaction involving a distributed database.

  

83. List the sequence of events when a large transaction that exceeds beyond its optimal value when an entry wraps and causes the rollback segment to expand into another extend.?

Transaction Begins.

An entry is made in the RES header for new transactions entry

Transaction acquires blocks in an extent of RBS

The entry attempts to wrap into second extent. None is available, so that the RBS must extent.

The RBS checks to see if it is part of its OPTIMAL size.

RBS chooses its oldest inactive segment.

Oldest inactive segment is eliminated.

RBS extents

The data dictionary tables for space management are updated.

Transaction Completes.

  

84. How can we plan storage for very large tables?

Limit the number of extents in the table

Separate table from its indexes.

Allocate sufficient temporary storage.

  

85. How will you estimate the space required by a non-clustered tables?

Calculate the total header size

Calculate the available data space per data block

Calculate the combined column lengths of the average row

Calculate the total average row size.

Calculate the average number rows that can fit in a block

Calculate the number of blocks and bytes required for the table.

After arriving the calculation, add 10 % additional space to calculate the initial extent size for a working table.

  

86. It is possible to use raw devices as data files and what are the advantages over file system files?

Yes.

The advantages over file system files are that I/O will be improved because Oracle is bye-passing the kernel which writing into disk. Disk corruption will be very less.

  

87. What is a Control file?

Database's overall physical architecture is maintained in a file called control file. It will be used to maintain internal consistency and guide recovery operations. Multiple copies of control files are advisable.

  

88. How to implement the multiple control files for an existing database?

Shutdown the database

Copy one of the existing control-file to new location

Edit Config ora file by adding new control filename

Restart the database.

  

89. What is redo log file mirroring?  How can be achieved?

Process of having a copy of redo log files is called mirroring.

This can be achieved by creating group of log files together, so that LGWR will automatically writes them to all the members of the current on-line redo log group. If any one group fails then database automatically switch over to next group. It degrades performance.

90. What is advantage of having disk shadowing / mirroring?

Shadow set of disks save as a backup in the event of disk failure. In most operating systems if any disk failure occurs it automatically switch over to place of failed disk.

Improved performance because most OS support volume shadowing can direct file I/O request to use the shadow set of files instead of the main set of files. This reduces I/O load on the main set of disks.

  

91. What is use of rollback segments in Oracle database?

They allow the database to maintain read consistency between multiple transactions.

92. What is a rollback segment entry?

It is the set of before image data blocks that contain rows that are modified by a transaction.

Each rollback segment entry must be completed within one rollback segment.

A single rollback segment can have multiple rollback segment entries.

93. What is hit ratio?

It is a measure of well the data cache buffer is handling requests for data.

Hit Ratio = (Logical Reads - Physical Reads - Hits Misses)/ Logical Reads.

94. When will be a segment released?

When Segment is dropped.

When Shrink (RBS only)

When truncated (TRUNCATE used with drop storage option)

95. What are disadvantages of having raw devices?

We should depend on export/import utility for backup/recovery (fully reliable)

The tar command cannot be used for physical file backup, instead we can use dd command, which is less flexible and has limited recoveries.

96. List the factors that can affect the accuracy of the estimations?

The space used transaction entries and deleted records, does not become free immediately after completion due to delayed clean out.

Trailing nulls and length bytes are not stored.

Inserts of, updates to and deletes of rows as well as columns larger than a single data block, can cause fragmentation a chained row pieces.

          Database Security & Administration

 97. What is user Account in Oracle database?

A user account is not a physical structure in database but it is having important relationship to the objects in the database and will be having certain privileges.

98. How will you enforce security using stored procedures?

Don't grant user access directly to tables within the application.

Instead grant the ability to access the procedures that access the tables.

When procedure executed it will execute the privilege of procedures owner. Users cannot access tables except via the procedure.

99. What are the dictionary tables used to monitor a database space?

 DBA_FREE_SPACE

DBA_SEGMENTS

DBA_DATA_FILES.

SQL*Plus Statements

  

100. What are the types of SQL statement?

 Data Definition Language: CREATE, ALTER, DROP, TRUNCATE, REVOKE, NO AUDIT & COMMIT.

 Data Manipulation Language: INSERT, UPDATE, DELETE, LOCK TABLE, EXPLAIN PLAN & SELECT.

Transitional Control: COMMIT & ROLLBACK

 Session Control: ALTER SESSION & SET ROLE

System Control: ALTER SYSTEM.

101. What is a transaction?

Transaction is logical unit between two commits and commit and rollback.

  

102. What is difference between TRUNCATE & DELETE?

 TRUNCATE commits after deleting entire table i.e., cannot be rolled back.

 Database triggers do not fire on TRUNCATE

DELETE allows the filtered deletion. Deleted records can be rolled back or committed.

Database triggers fire on DELETE.

  

103. What is a join? Explain the different types of joins?

 Join is a query, which retrieves related columns or rows from multiple tables.

Self Join - Joining the table with itself.

Equi Join - Joining two tables by equating two common columns.

Non-Equi Join - Joining two tables by equating two common columns.

Outer Join - Joining two tables in such a way that query can also retrieve rows that do not have corresponding join value in the other table.

104. What is the sub-query?

Sub-query is a query whose return values are used in filtering conditions of the main query.

105. What is correlated sub-query?

Correlated sub-query is a sub-query, which has reference to the main query.

  

106. Explain CONNECT BY PRIOR?

Retrieves rows in hierarchical order eg.

select empno, ename from emp where.

107. Difference between SUBSTR and INSTR?

INSTR (String1, String2 (n, (m)),

INSTR returns the position of the m-th occurrence of the string 2 in string1. The search begins from nth position of string1.

SUBSTR (String1 n, m)

SUBSTR returns a character string of size m in string1, starting from n-th position of string1.

108. Explain UNION, MINUS, UNION ALL and INTERSECT?

 INTERSECT   - returns all distinct rows selected by both queries.

MINUS            - returns all distinct rows selected by the first query but not by the second.

UNION            - returns all distinct rows selected by either query

UNION ALL    - returns all rows selected by either query, including all duplicates.

109. What is ROWID?

ROWID is a pseudo column attached to each row of a table. It is 18 characters long, blockno, rownumber are the components of ROWID.

110. What is the fastest way of accessing a row in a table?

Using ROWID.

CONSTRAINTS

111. What is an integrity constraint?

Integrity constraint is a rule that restricts values to a column in a table.

112. What is referential integrity constraint?

Maintaining data integrity through a set of rules that restrict the values of one or more columns of the tables based on the values of primary key or unique key of the referenced table.

113. What is the usage of SAVEPOINTS?

SAVEPOINTS are used to subdivide a transaction into smaller parts. It enables rolling back part of a transaction. Maximum of five save points are allowed.

114.  What is ON DELETE CASCADE?

 When ON DELETE CASCADE is specified Oracle maintains referential integrity by automatically removing dependent foreign key values if a referenced primary or unique key value is removed.

115. What are the data types allowed in a table?

 CHAR, VARCHAR2, NUMBER, DATE, RAW, LONG and LONG RAW.

116. What is difference between CHAR and VARCHAR2?  What is the maximum SIZE allowed for each type?

CHAR pads blank spaces to the maximum length.

VARCHAR2 does not pad blank spaces.

For CHAR the maximum length is 255 and 2000 for VARCHAR2.

117.  How many LONG columns are allowed in a table? Is it possible to use LONG columns in WHERE clause or ORDER BY? 

Only one LONG column is allowed. It is not possible to use LONG column in WHERE or ORDER BY clause.

118. What are the pre-requisites to modify datatype of a column and to add a column with NOT NULL constraint?

 To modify the datatype of a column the column must be empty.

 To add a column with NOT NULL constrain, the table must be empty.

 119. Where the integrity constraints are stored in data dictionary?

 The integrity constraints are stored in USER_CONSTRAINTS. 

120. How will you activate/deactivate integrity constraints?

 The integrity constraints can be enabled or disabled by ALTER TABLE ENABLE CONSTRAINT / DISABLE CONSTRAINT.

121. If unique key constraint on DATE column is created, will it validate the rows that are inserted with SYSDATE?

It won't, Because SYSDATE format contains time attached with it.

122. What is a database link?

Database link is a named path through which a remote database can be accessed.

123. How to access the current value and next value from a sequence? Is it possible to access the current value in a session before accessing next value?

Sequence name CURRVAL, sequence name NEXTVAL. It is not possible. Only if you access next value in the session, current value can be accessed.

124. What is CYCLE/NO CYCLE in a Sequence?

CYCLE specifies that the sequence continue to generate values after reaching either maximum or minimum value. After pan-ascending sequence reaches its maximum value, it generates its minimum value. After a descending sequence reaches its minimum, it generates its maximum. 

NO CYCLE specifies that the sequence cannot generate more values after reaching its maximum or minimum value.

125. What are the advantages of VIEW?

- To protect some of the columns of a table from other users.

- To hide complexity of a query.

- To hide complexity of calculations.

126. Can a view be updated/inserted/deleted? If Yes - under what conditions?

 A View can be updated/deleted/inserted if it has only one base table if the view is based on columns from one or more tables then insert, update and delete is not possible.

127. If a view on a single base table is manipulated will the changes be reflected on the base table?

If changes are made to the tables and these tables are the base tables of a view, then the changes will be reference on the view.

OS relates interview questions for DBA Professional:

1. How do you list the files in an UNIX directory while also showing hidden files?

ls -ltra

2. How do you execute a UNIX command in the background?

Use the "&"

  

3. What UNIX command will control the default file permissions when files are created?

Umask

4. Explain the read, write, and execute permissions on a UNIX directory.?

 Read allows you to see and list the directory contents.

 Write allows you to create, edit and delete files and sub-directories in the directory.

 Execute gives you the previous read/write permissions plus allows you to change into the directory and execute programs or shells from the directory.

5. the difference between a soft link and a hard link?

 A symbolic (soft) linked file and the targeted file can be located on the same or different file system while for a hard link they must be located on the same file system.

  

6. Give the command to display space usage on the UNIX file system.?

 df -lk

7. Explain iostat, vmstat and netstat.?

 Iostat reports on terminal, disk and tape I/O activity.

 Vmstat reports on virtual memory statistics for processes, disk, tape and CPU activity.

 Netstat reports on the contents of network data structures.

8. How would you change all occurrences of a value using VI?

 Use :%s///g

  

9. Give two UNIX kernel parameters that effect an Oracle install?

 SHMMAX & SHMMNI

  

10. Briefly, how do you install Oracle software on UNIX.?

Basically, set up disks, kernel parameters, and run orainst..