1.  What are  the  components of Physical database     structure of Oracle Database?.

ORACLE  database  is  comprised  of  three types of files. One or more Data files, two are more Redo Log files, and one or more Control files.

2.  What  are  the  components  of  Logical  database  structure  of ORACLE database?

Tablespaces and the Database's Schema Objects.

3. What is a Tablespace?

A  database  is  divided  into  Logical  Storage Unit called tablespaces. A tablespace is used to grouped related logical structures together.

4. What is SYSTEM tablespace and When is it Created?

Every  ORACLE  database  contains  a  tablespace  named  SYSTEM,  which  is automatically  created  when the database is created. The SYSTEM tablespace always contains the data dictionary tables for the entire database.

5. Explain the relationship among Database, Tablespace and Data file.

Each  database is  logically divided into one or more tablespaces One or more data files are explicitly created for each tablespace.

6. What is schema?

A schema is collection of database objects of a User.

7. What are Schema Objects ?
Schema objects are the logical structures that directly refer to the database’s data.  Schema objects include tables, views, sequences, synonyms, indexes, clusters, database triggers, procedures, functions packages and database links.

8. Can objects of the same Schema reside in different tablespaces?
Yes.

9. Can a Tablespace hold objects from different Schemes?
Yes.

10. What is Table?
A table is the basic unit of data storage in an ORACLE database. The tables of a database hold all of the user accessible data. Table data is stored in rows and columns.

11. What is a View?

A  view  is  a  virtual  table. Every view has a Query attached to it. (The Query  is  a  SELECT  statement that identifies the columns and rows of the table(s) the view uses.)

12. Do  View contain Data ?

Views do not contain or store data.

13. Can a  View based on another View ?

Yes.

14. What are the advantages of Views ?

Provide  an  additional level of table security, by restricting access to a predetermined set of rows and columns of a table.
Hide data complexity.
Simplify commands for the user.
Present the data in a different perpecetive from that of the base table.
Store complex queries.

15. What is a Sequence ?

A  sequence generates a serial list of unique numbers for numerical columns of a database's tables.

16.  What is a Synonym ?

A synonym is an alias for a table, view, sequence or program unit.

17. What are the type of Synonyms?

There are two types of Synonyms Private and Public.

18. What is a Private Synonyms ?

A Private Synonyms can be accessed only by the owner.

19. What is a Public Synonyms ?

A Public synonyms can be accessed by any user on the database.

20. What are synonyms used for ?

Synonyms are used to: Mask the real name and owner of an object.
Provide public access to an object
Provide location transparency for tables, views or program units of a remote database.
Simplify the SQL statements for database users.


21. What is an Index ?

An Index is an optional structure associated with a table to have direct access to rows, which can be created to increase the performance of data retrieval.  Index can be created on one or more columns of a table.


22.  How are Indexes Update ?

Indexes are automatically maintained and used by ORACLE. Changes to table data are automatically incorporated into all relevant indexes.

23. What are Clusters?

Clusters are groups of one or more tables physically stores together to share common columns and are often used together.

24. What is cluster Key?

The related columns of the tables in a cluster are called the Cluster Key.

25. What is Index Cluster ?

A Cluster with an index on the Cluster Key.

26. What is Hash Cluster ?

A row is stored in a hash cluster based on the result of applying a hash function to the row's cluster key value. All rows with the same hash key value are stores together on disk.

27. When can Hash Cluster used ?

Hash clusters are better choice when a table is often queried with equality queries.  For  such  queries the specified cluster key value is hashed. The resulting  hash  key  value points directly to the area on disk that stores the specified rows.

28. What is  Database Link ?

A database link is a named object that describes a "path" from one database to another.

29. What are the types of Database Links?

Private Database Link, Public Database Link & Network Database Link.

30. What is Private Database Link ?

Private  database  link  is created on behalf of a specific user. A private database  link  can  be  used  only  when the owner of the link specifies a global  object  name in a SQL statement or in the definition of the owner's views or procedures.

31. What is Public Database Link ?

Public database link is created for the special user group PUBLIC. A public database  link  can  be  used  when  any  user  in  the associated database specifies a global object name in a SQL  statement or object definition.



32.  What is Network Database link ?

Network database link is created and managed by a network domain service. A network  database  link  can  be  used when any user of any database in the network  specifies  a  global  object  name  in  a  SQL statement or object definition.

33. What is Data Block ?

ORACLE database's data is stored in data blocks. One data block corresponds to a specific number of bytes of physical database space on disk.

34. How to define Data Block size ?

A  data  block size is specified for each ORACLE database when the database is  created.  A  database users and allocated free database space in ORACLE datablocks.  Block size is specified in INIT.ORA file and cann't be changed latter.

35. What is Row Chaining ?

In  Circumstances,  all of the data for a row in a table may not be able to fit  in  the  same  data  block. When this occurs , the data for the row is stored in a chain of data block (one or more) reserved for that segment.

36. What is an Extent ?

An   Extent  is  a specific number of contiguous data blocks, obtained in a single allocation, used to store a specific type of information.

37.  What is a Segment ?

A segment is a set of extents allocated for a certain logical structure.

38. What are the different type of Segments ?

Data Segment, Index Segment, Rollback Segment and Temporary Segment.

39. What is a Data Segment ?

Each  Non-clustered  table  has  a data segment. All of the table's data is stored in the extents of its data segment. Each cluster has a data segment. The  data  of  every  table  in the cluster is stored in the cluster's data segment.

40. What is an Index Segment ?

Each Index has an Index segment that stores all of its data.

41. What is  Rollback Segment ?

A  Database  contains  one  or  more Rollback Segments to temporarily store "undo" information.

42. What are the uses of Rollback Segment ?

Rollback Segments are used :
To  generate  read-consistent database information during database recovery to rollback uncommitted transactions for users.

43. What is a Temporary Segment ?

Temporary  segments  are  created  by  ORACLE  when a SQL statement needs a temporary  work  area  to  complete  execution. When the statement finishes execution,  the  temporary  segment  extents are released to the system for future use.

44. What is a Data File ?

Every  ORACLE  database  has  one or more physical data files. A database's data  files  contain  all  the  database data. The data of logical database structures  such  as  tables  and  indexes is physically stored in the data files allocated for a database.

45. What are the Characteristics of Data Files ?

A  data  file  can be associated with only one database. Once created a data file can't change size.
One  or  more  data  files form a logical unit of database storage called a table space.

46. What is a Redo Log?

The  set  of  Redo  Log  files  for a database is collectively known as the database's redo log.

47. What is the function of Redo Log ?

The Primary function of the redo log is to record all changes made to data.

48. What is the use of Redo Log Information ?

The Information in a redo log file is used only to recover the database from a system or media failure prevents database data from being written to a database's data files.

49. What does a Control file Contain ?

A  Control file records the physical structure of the database. It contains the following information.

Database Name
Names and locations of a database's files and redolog files.
Time stamp of database creation.

50. What is the use of Control File ?

When an instance of an ORACLE database is started, its control file is used to  identify  the  database  and  redo  log  files  that must be opened for database operation to proceed. It is also used in database recovery.

51. What is a Data Dictionary ?

The data dictionary of an ORACLE database is a set of tables and views that are used  as a read-only reference about the database.
It  stores information about both the logical and physical structure of the database,  the  valid  users  of  an ORACLE database, integrity constraints defined  for tables in the database and space allocated for a schema object and how much of it is being used.

52. What is an Integrity Constrains ?

An  integrity constraint is a declarative way to define a business rule for a column of a table.

53.  Can  an  Integrity  Constraint be enforced on a table if some existing table data does not satisfy the constraint ?
No.

54.  Describe  the  different  type  of  Integrity Constraints supported by ORACLE ?
NOT NULL Constraint    - Disallows NULLs in a table's column.
UNIQUE   Constraint      - Disallows duplicate values in a column or set of columns.
PRIMARY  KEY  Constraint - Disallows duplicate values and NULLs in a column or set of columns.
FOREIGN  KEY   Constrain - Require each value in a column or set of columns match a value in a related table's UNIQUE or PRIMARY KEY.
CHECK  Constraint        - Disallows values that do not satisfy the logical expression of the constraint.

55. What is difference between UNIQUE constraint and PRIMARY KEY constraint ?
A  column  defined  as   UNIQUE can contain NULLs while a column defined as PRIMARY KEY can't contain Nulls.

56. Describe Referential Integrity ?

A rule defined on a column (or set of columns) in one table that allows the insert  or  update  of  a  row  only  if the value for the column or set of columns  (the  dependent  value)  matches  a value in a column of a related table   (the  referenced  value).  It  also  specifies  the  type  of  data manipulation  allowed  on referenced data and the action to be performed on dependent data as a result of any action on referenced data.

57.  What  are  the  Referential actions supported by FOREIGN KEY integrity constraint ?

UPDATE  and  DELETE  Restrict - A referential integrity rule that disallows the update or deletion of referenced data.

DELETE  Cascade - When a referenced row is deleted all associated dependent rows are deleted.

58. What is self-referential integrity constraint ?
If  a  foreign  key  reference  a  parent  key  of the same table is called self-referential integrity constraint.

59. What are the Limitations of a CHECK Constraint ?

The  condition  must  be a Boolean expression evaluated using the values in the row being inserted or updated and can't contain subqueries, sequence, the SYSDATE,UID,USER  or  USERENV  SQL functions, or the pseudo columns LEVEL or ROWNUM.

60.  What is the maximum number of CHECK constraints that can be defined on a column ?
No Limit.


SYSTEM ARCHITECTURE :

61. What constitute an ORACLE Instance ?
SGA  and  ORACLE  background  processes constitute an ORACLE instance. (or) Combination of memory structure and background process.

62. What is SGA ?
The  System Global Area (SGA) is a shared memory region allocated by ORACLE that contains data and control information for one ORACLE instance.

63. What are the components of SGA ?
Database buffers, Redo Log Buffer the Shared Pool and   Cursors.

 64. What do Database Buffers contain ?

Database  buffers store the most recently  used blocks of database data. It can also contain modified data that has not yet been permanently written to disk.

65. What do Redo Log Buffers contain ?
Redo Log Buffer stores redo entries a log of changes made to the database.

66. What is Shared Pool ?
Shared  Pool is a portion of the SGA that contains shared memory constructs such as shared SQL areas.

67. What is Shared SQL Area ?
A  Shared  SQL  area  is  required  to  process  every unique SQL statement submitted to a database and contains information such as the parse tree and execution plan for the corresponding statement.

68. What is Cursor ?
A  Cursor is a handle ( a name or pointer) for the memory associated with a specific statement.

69. What is PGA ?
Program Global Area (PGA) is a memory buffer that contains data and control information for a server process.

70. What is User Process ?
A user process is created and maintained to execute the software code of an application  program.  It  is  a  shadow  process  created automatically to facilitate communication between the user and the server process.

71. What is Server Process ?
Server  Process  handle  requests  from  connected  user  process. A server process is in charge of communicating with the user process and interacting with ORACLE carry out requests of the associated user process.

72. What are the two types of Server Configurations ?
Dedicated Server Configuration and Multi-threaded Server Configuration.

73. What is Dedicated Server Configuration ?
In a Dedicated Server Configuration a Server Process handles requests for a Single User Process.

74. What is a Multi-threaded Server Configuration ?
In  a Multi-threaded Server Configuration many user processes share a group of server process.

75. What is a Parallel Server option in ORACLE ?
A configuration for loosely coupled systems where multiple instance share a single physical database is called Parallel Server.

76. Name the ORACLE Background Process ?
DBWR - Database Writer.
LGWR - Log Writer
CKPT - Check Point
SMON - System Monitor
PMON - Process Monitor
ARCH - Archiver
RECO - Recover
Dnnn - Dispatcher, and
LCKn - Lock
Snnn - Server.

77.  What Does DBWR do ?
Database  writer  writes  modified blocks from the database buffer cache to the data files.

78.When Does DBWR write to the database ?
DBWR  writes  when  more  data  needs  to  be read into the SGA and too few database  buffers  are free. The least recently used data is written to the data files first. DBWR also writes when CheckPoint occurs.

79. What does LGWR do ?
Log  Writer (LGWR) writes redo log entries generated in the redo log buffer of the SGA to on-line Redo Log File.

80. When does LGWR write to the database?
LGWR writes redo log entries into an on-line redo log file when transactions commit and the log buffer files are full.

81. What is the function of checkpoint CKPT)?
The Checkpoint  (CKPT) process is responsible for signaling DBWR at checkpoints and updating all the data files and control files of the database.

82. What are the functions of SMON ?
System  Monitor (SMON)  performs instance recovery at instance start-up. In a multiple instance system (one that uses the Parallel Server), SMON of one instance  can  also  perform instance recovery for other instance that have failed SMON also cleans up temporary segments that are no longer in use and recovers  dead  transactions  skipped  during  crash  and instance recovery because of  file-read or off-line errors. These transactions are eventually recovered  by SMON when the tablespace or file is brought back on-line SMON also  coalesces  free  extents  within  the  database  to  make  free space contiguous and easier to allocate.

83.  What are functions of PMON ?
Process Monitor (PMON)  performs process recovery when a user process fails PMON  is  responsible  for cleaning up the cache and Freeing resources that the  process  was using PMON also checks on dispatcher and server processes and restarts them if they have failed.

84.  What is the function of ARCH ?
Archiver  (ARCH) copies the on-line redo log files to archival storage when they  are  full.  ARCH is active only when a database's redo log is used in ARCHIVELOG mode.

85. What is function of RECO ?
RECOver (RECO) is used to resolve distributed transactions that are pending due  to  a  network  or  system failure in a distributed database. At timed intervals,the  local  RECO  attempts  to  connect  to  remote databases and automatically  complete  the commit or rollback of the local portion of any pending distributed transactions.

86. What is the function of Dispatcher (Dnnn) ?
Dispatcher   (Dnnn)  process  is  responsible  for  routing  requests  from connected user processes to available shared server processes and returning the responses back to the appropriate user processes.

87. How many Dispatcher Processes are created ?
Atleast one Dispatcher process is created for every communication protocol in use.

88. What is the function of Lock (LCKn) Process ?
Lock  (LCKn)  are  used for inter-instance locking when the ORACLE Parallel Server option is used.

89. What is the maximum number of Lock Processes used ?
Though  a single LCK process is sufficient for most Parallel Server systems
upto Ten Locks (LCK0,....LCK9) are used for inter-instance locking.






DATA ACCESS

90. Define Transaction ?
A  Transaction  is  a  logical  unit of work that comprises one or more SQL statements executed by a single user.


91. When does a Transaction end ?
When it is committed or Rollbacked.

92. What does COMMIT do ?
COMMIT makes permanent the changes resulting from all SQL statements in the transaction. The changes made by the SQL statements of a transaction become visible   to  other  user  sessions  transactions  that  start  only  after transaction is committed.

93. What does ROLLBACK do ?
ROLLBACK  retracts  any of the changes resulting from the SQL statements in the transaction.

94. What is SAVE POINT ?
For  long  transactions  that  contain  many  SQL  statements, intermediate markers  or  savepoints  can  be  declared  which  can  be used to divide a transaction  into  smaller  parts.  This allows the option of later rolling back  all  work  performed  from  the current point in the transaction to a declared savepoint within the transaction.

95. What is Read-Only Transaction ?
A  Read-Only transaction ensures that the results of each query executed in the transaction are consistant with respect to the same point in time.

96. What is the function of Optimizer ?

The  goal of the optimizer is to choose the most efficient way to execute a SQL statement.

97. What is Execution Plan ?
The  combinations of the steps the optimizer chooses to execute a statement is called an execution plan.

98.   What  are  the  different approaches used by Optimizer in choosing an execution plan ?
Rule-based and Cost-based.

99.  What are the factors that affect OPTIMIZER in choosing an Optimization approach ?
The   OPTIMIZER_MODE   initialization  parameter  Statistics  in  the  Data Dictionary  the OPTIMIZER_GOAL parameter of the ALTER SESSION command hints in the statement.

100. What are the values that can be specified for OPTIMIZER MODE Parameter ?
COST and RULE.

101. Will the Optimizer always use COST-based approach if OPTIMIZER_MODE is set to "Cost'?

Presence of statistics in the data dictionary for atleast one of the tables accessed  by  the  SQL  statements  is  necessary  for the OPTIMIZER to use COST-based approach. Otherwise OPTIMIZER chooses RULE-based approach.

102. What is the effect of setting the value of OPTIMIZER_MODE to 'RULE' ?

This  value  causes the optimizer to choose the rule_based approach for all SQL  statements  issued  to  the  instance  regardless  of  the presence of statistics.

103. What are the values that can be specified for OPTIMIZER_GOAL parameter of the ALTER SESSION Command ?

CHOOSE,ALL_ROWS,FIRST_ROWS and RULE.

104.  What  is the effect of setting the value "CHOOSE" for OPTIMIZER_GOAL, parameter of the ALTER SESSION Command ?
The  Optimizer  chooses  Cost_based approach and optimizes with the goal of best throughput if statistics for atleast one of the tables accessed by the SQL statement exist in the data dictionary. Otherwise the OPTIMIZER chooses RULE_based approach.

105. What is the effect of setting the value "ALL_ROWS"  for OPTIMIZER_GOAL parameter of the ALTER SESSION  command ?
This  value  causes  the  optimizer to the cost-based approach for  all SQL statements  in  the session regardless of the presence of statistics and to optimize with a goal of best throughput.

106.    What   is   the  effect  of  setting  the  value  'FIRST_ROWS'  for OPTIMIZER_GOAL parameter of the ALTER SESSION command ?
This  value causes the optimizer to use the cost-based approach for all SQL statements  in  the session regardless of the presence of statistics and to optimize with a goal of best response time.

107.  What  is the effect of setting the 'RULE' for OPTIMIER_GOAL parameter of the ALTER SESSION Command ?
This  value  causes the optimizer to choose the rule-based approach for all SQL statements in a session regardless of the presence of statistics.

108. What is RULE-based approach to optimization ?
Choosing an executing planbased on the access paths available and the ranks of these access paths.

109. What is COST-based approach to optimization ?
Considering  available  access  paths  and  determining  the most efficient execution  plan  based  on statistics in the data dictionary for the tables accessed by the statement and their associated  clusters and indexes.



PROGRAMMATIC CONSTRUCTS

110.  What  are  the  different  types  of PL/SQL program units that can be defined and stored in ORACLE database ?

Procedures and Functions,Packages and Database Triggers.

111. What is a Procedure ?
A  Procedure consist of a set of SQL and PL/SQL statements that are grouped together  as a unit to solve a specific problem or perform a set of related tasks.

112. What is difference between Procedures and Functions ?
A Function returns a value to the caller where as a Procedure does not.

113. What is a Package ?
A  Package  is a collection of related procedures, functions, variables and other package constructs together as a unit in the database.

114. What are the advantages of having a Package ?
Increased  functionality  (for  example,global  package  variables  can  be declared  and  used  by  any proecdure in the package) and performance (for example  all  objects  of  the package are parsed compiled, and loaded into memory once)

115. What is Database Trigger ?
A Database Trigger is procedure (set of SQL  and PL/SQL statements) that is automatically  executed  as  a  result of an insert in,update to, or delete from a table.

116. What are the uses of Database Trigger ?
Database  triggers  can  be  used  to automatic data generation, audit data modifications, enforce complex Integrity constraints, and customize complex security authorizations.

117.  What  are  the  differences  between  Database  Trigger and Integrity constraints ?
A  declarative  integrity constraint is a statement about the database that is  always true. A constraint applies to existing data in the table and any statement that manipulates the table.

A  trigger  does  not  apply  to  data  loaded before the definition of the trigger,  therefore,  it does not guarantee all data in a table conforms to the rules established by an associated trigger.

A  trigger  can  be  used  to  enforce  transitional constraints where as a declarative integrity constraint cannot be used.


DATABASE SECURITY

118.  What are Roles ?
Roles  are  named groups of related privileges that are granted to users or other roles.

119. What are the use of Roles ?
REDUCED  GRANTING  OF PRIVILEGES - Rather than explicitly granting the same set  of  privileges  to  many users a database administrator  can grant the privileges  for  a  group of related users granted to a role and then grant only the role to each member of the group.

DYNAMIC PRIVILEGE MANAGEMENT  - When the privileges of a group must change, only  the  privileges of the role need to be modified. The security domains of  all  users  granted  the group's role automatically reflect the changes made to the role.

SELECTIVE  AVAILABILITY  OF PRIVILEGES - The roles granted to a user can be selectively  enable  (available  for  use)  or disabled  (not available for use).  This  allows  specific  control  of a user's privileges in any given situation.

APPLICATION   AWARENESS  -  A  database  application  can  be  designed  to automatically  enable  and  disable selective roles when a user attempts to use the application.

120. How to prevent unauthorized use of privileges granted to a Role ?
By creating a Role with a password.

121. What is default tablespace ?
The  Tablespace  to  contain  schema  objects  created without specifying a tablespace name.

122. What is Tablespace Quota ?
The collective amount of disk space available to the objects in a schema on a particular tablespace.

123. What is a profile ?
Each  database  user  is  assigned  a Profile that specifies limitations on various system resources available to the user.

124. What are the system resources that can be controlled through Profile ?
The number of concurrent sessions the user can establish the CPU processing time available to the user's session the CPU processing time available to a single  call  to  ORACLE  made by a SQL statement the amount of logical I/O available  to  the  user's  session the amout of logical I/O available to a single  call  to  ORACLE made by a SQL statement the allowed amount of idle time  for  the  user's  session  the allowed amount of connect time for the user's session.

125. What is Auditing ?
Monitoring of user access to aid in the investigation of database use.

126. What are the different Levels of Auditing ?
Statement Auditing, Privilege Auditing and Object Auditing.

127. What is Statement Auditing ?
Statement  auditing  is  the  auditing  of  the  powerful system privileges without regard to specifically named objects.

128. What is Privilege Auditing ?
Privilege auditing is the auditing of the use of powerful system privileges without regard to specifically named objects.

129. What is Object  Auditing ?
Object  auditing  is  the  auditing  of accesses to specific schema objects without regard to user.


DISTRIBUTED PROCESSING AND DISTRIBUTED DATABASES

130. What is Distributed database ?
A  distributed  database  is  a  network  of  databases managed by multiple database  servers  that  appears  to a user as single logical database. The data  of  all  databases  in the distributed database can be simultaneously accessed and modified.

131.  What is Two-Phase Commit ?
Two-phase  commit  is  mechanism  that guarantees a distributed transaction either commits on all involved nodes or rolls back on all involved nodes to maintain  data  consistency  across the global distributed database. It has two phase, a Prepare Phase and a Commit Phase.

132. Describe two phases of Two-phase commit ?
Prepare phase - The global coordinator (initiating node) ask a participants to  prepare   (to  promise  to  commit or rollback the transaction, even if there is a  failure)

Commit  -  Phase - If all participants respond to the coordinator that they are  prepared, the coordinator asks all nodes to commit the transaction, if all  participants  cannot  prepare,  the coordinator asks all nodes to roll back the transaction.

133. What is the mechanism provided by ORACLE for table replication ?
Snapshots and SNAPSHOT LOGs

134. What is a SNAPSHOT ?
Snapshots  are  read-only copies of a master table located on a remote node which  is  periodically  refreshed  to  reflect  changes made to the master table.

135. What is a SNAPSHOT LOG ?
A  snapshot  log  is a table in the master database that is associated with the  master  table.  ORACLE uses a snapshot log to track the rows that have been  updated  in  the master table. Snapshot logs are used in updating the snapshots based on the master table.

136. What is a SQL * NET?
SQL  *NET  is  ORACLE's  mechanism  for  interfacing with the communication protocols  used  by the networks that facilitate distributed processing and distributed  databases.  It  is  used  in  Clint-Server  and  Server-Server communications.

DATABASE OPERATION, BACKUP AND RECOVERY

137. What are the steps involved in Database Startup ?
Start an instance, Mount the Database and Open the Database.

138. What are the steps involved in Database Shutdown ?
Close the Database, Dismount the Database and Shutdown the Instance.

139. What is  Restricted Mode of Instance Startup ?
An  instance  can be started in (or later altered to be in) restricted mode so  that  when  the  database is open connections are limited only to those whose  user  accounts  have  been  granted  the  RESTRICTED  SESSION system privilege.

140.  What are the different modes of mounting a Database with the Parallel Server ?

Exclusive  Mode  If  the  first  instance that mounts a database does so in exclusive mode, only that Instance can mount the database.

Parallel  Mode   If the first instance that mounts a database is started in parallel  mode,  other instances that are started in parallel mode can also mount the database.

141. What is Full Backup ?
A full backup is an operating system backup of all data files, on-line redo log  files  and  control  file  that  constitute  ORACLE  database  and the parameter.

142. Can Full Backup be performed when the database is open ?
No.

143. What is Partial Backup ?
A   Partial  Backup  is any operating system backup short of a full backup, taken while the database is open or shut down.

144.WhatisOn-lineRedoLog?
The On-line Redo Log is a set of tow or more on-line redo files that record all  committed  changes  made  to  the  database. Whenever a transaction is committed,  the  corresponding  redo entries temporarily stores in redo log buffers  of  the  SGA  are  written  to  an  on-line  redo  log file by the background  process  LGWR.  The on-line redo log files are used in cyclical fashion.

145.  What is Mirrored on-line Redo Log ?
A  mirrored  on-line  redo log consists of copies of on-line redo log files physically  located  on  separate  disks, changes made to one member of the group are made to all members.

146. What is Archived Redo Log ?
Archived  Redo  Log  consists  of Redo Log files that have         archived before being reused.

147.  What  are  the  advantages of operating a database in ARCHIVELOG mode over operating it in NO ARCHIVELOG mode ?
Complete database recovery from disk failure is possible only in ARCHIVELOG mode.
Online database backup is possible only in ARCHIVELOG     mode.

148. What is Log  Switch ?
The  point  at  which  ORACLE  ends writing to one online redo log file and begins writing to another is called a log switch.

149. What are the steps involved in Instance  Recovery ?
R_olling  forward to recover data that has not been recorded in data files, yet  has  been recorded  in the on-line redo log, including the contents of rollback segments.

Rolling back transactions that have been explicitly rolled back or have not been committed as indicated by the rollback segments regenerated in step a.
Releasing any resources (locks) held by transactions in process at the time of the failure.

Resolving  any  pending  distributed  transactions  undergoing  a two-phase commit at the time of the instance failure.


Data Base Administration

Introduction to DBA

1. 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 process can be shared by all users.

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

2. What is Parallel Server ?

Multiple   instances   accessing  the  same  database  (Only  In  Multi-CPU environments)


3. What is a Schema ?

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

4.  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 comman (Ver 7.0)

5. What is clusters ?

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

6. 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.

7. 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

8. What is a deadlock ? Explain .

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

In  a  database  environment  this will often happen because of not issuing 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

9. What is SGA ? How it is different from  Ver 6.0 and Ver 7.0 ?

The  System   Global  Area  in  a  Oracle database is the area in memory to facilitates  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 SQL pool (ver 7.0 only) area.

10. What is a Shared SQL pool ?

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

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

It is area in memory that is used by a Single Oracle User Process.

12. 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.

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

Due to insufficient Shared SQL 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.

LOGICAL & PHYSICAL ARCHITECTURE OF DATABASE.

14. 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.

15. What is dictionary cache ?

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

16. 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.

17. What is meant by redo log buffer ?

Change  made  to entries 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.

18.  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.

19.  List  the Optional Flexible Architecture (OFA) of Oracle database ? or How  can  we  organise  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.

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

SET TRANSACTION USE ROLLBACK SEGMENT rbs_name.

21. 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.

22. How free extents are managed in Ver 6.0 and Ver 7.0 ?

Free extents cannot be merged together in Ver 6.0.
Free extents are periodically coalesces with the neighboring free extent in
Ver 7.0

23.Which parameter in Storage clause will reduce no. of rows per block?

PCTFREE parameter

Row size also reduces no of rows per block.

24. 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 updations etc.,

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

Each block contains entries as follows
Fixied block header
Variable block header
Row Header,row date (multiple rows may exists)
PCTEREE (% of  free space for row updation in future)

26. 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.

27. What is the OPTIMAL parameter ?

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

28. 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.

29. 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.

30. How the space utilisation 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 (No. of extents is based on the optimal size)

31. Why query fails sometimes ?

Rollback  segment  dynamically  extent  to handle larger transactions entry loads.

A  single  transaction may wipeout all avaliable free space in the Rollback Segment Tablespace. This prevents other user using Rollback segments.

32. How will you monitor the space allocation ?

By quering DBA_SEGMENT table/view.

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

34.  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 table for space management are updated.
Transaction Completes.

35. 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.

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

Calculate the total header size
Calculate the available dataspace 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.

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

Yes.

The advantages over file system files.

I/O  will  be  improved  because  Oracle  is  bye-passing the kernnel which writing into disk.
Disk Corruption will be very less.

38. 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.

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

Shutdown the databse
Copy one of the existing control file to new location
Edit Config ora file by adding new control file.name
Restart the database.

40. What is meant by Redo Log file mirrorring ? How it 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.

41. 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  System if any disk failure occurs it automatically switchover 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.

42. What is use of Rollback Segments In Database ?

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

43. 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.

44. 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.

45. When will be a segment released ?

When Segment is dropped.
When Shrink (RBS only)
When truncated (TRUNCATE used with drop storage option)

46. What are disadvanteges 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.

47. 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 cleanout.

Trailling nulls and length bytes are not stored.


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

DATABASE SECURITY & ADMINISTRATION

48. What is user Account in Oracle database ?

An  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.

49. 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.

50. What are the dictionary tables used to monitor a database spaces ?

DBA_FREE_SPACE
DBA_SEGMENTS
DBA_DATA_FILES.

51. What are the responsibilities of a Database Administrator ?

Installing and upgrading the Oracle Server and application tools.
Allocating  system storage and planning future storage requirements for the database  system.
Managing primary database structures (tablespaces)
Managing primary objects (table,views,indexes)
Enrolling users and maintaining system security.
Ensuring compliance with Oralce license agreement
Controlling and monitoring user access to the database.
Monitoring and optimising the performance of the database.
Planning for backup and recovery of database information.
Maintain archived data on tape
Backing up and restoring the database.
Contacting Oracle Corporation for technical support.


52.  What  are  the roles  and user accounts created automatically with the database ?

DBA - role Contains all database system privileges.

SYS  user  account  - The DBA role will be assigned to this account. All of the  basetables  and  views for the database's dictionary are store in this schema and are manipulated only by ORACLE.

SYSTEM user account - It has all the system privileges for the database and additional  tables  and  views  that display administrative information and internal  tables  and  views  used  by  oracle tools are created using this username.

54. What are the database administrators utilities avaliable ?

SQL * DBA - This allows DBA to monitor and control an ORACLE database.

SQL  *  Loader  -  It loads data from standard operating system files (Flat files) into ORACLE database tables.

Export  (EXP) and Import (imp) utilities allow you to move existing data in ORACLE format to and from ORACLE database.

55.  What  are  the  minimum  parameters should exist in the parameter file (init.ora) ?

DB  NAME  -  Must  set to a text string of no more than 8 characters and it will  be  stored inside the datafiles, redo log files and control files and control file while database creation.

DB_DOMAIN  -  It  is  string  that  specifies  the network domain where the database  is  created.  The  global  database name is identified by setting these parameters (DB_NAME & DB_DOMAIN)

CONTORL  FILES  - List of control filenames of the database. If name is not mentioned then default name will be used.

DB_BLOCK_BUFFERS  -  To  determine the no of buffers in the buffer cache in SGA.

PROCESSES  -  To determine number of operating system processes that can be connected  to  ORACLE  concurrently.  The  value  should  be  5 (background process) and additional 1 for each user.

ROLLBACK_SEGMENTS  -  List of rollback segments an ORACLE instance acquires at database startup.

Also     optionally     LICENSE_MAX_SESSIONS,LICENSE_SESSION_WARNING    and LICENSE_MAX_USERS.

56. What is a trace file and how is it created ?

Each server and background process can write an associated trace file. When an   internal  error  is  detected  by  a  process or user process, it dumps information  about  the error to its trace. This can be used for tuning the database.

57. What are roles ? How can we implement roles ?

Roles  are  the easiest way to grant and manage common privileges needed by different groups of database users.

Creating roles and assigning provies to roles.

Assign each role to group of users. This will simplify the job of assigning privileges to individual users.

58.  What  are the steps to switch a database's archiving mode between   NO ARCHIVELOG and ARCHIVELOG mode ?

     1. Shutdown the database instance.
     2. Backup the databse
     3. Perform any operating system specific steps (optional)
     4. Start up a new instance and mount but do not open the databse.
     5. Switch the databse's archiving mode.

59. How can you enable automatic archiving ?

     Shut the database
     Backup the database
     Modify/Include LOG_ARCHIVE_START_TRUE in init.ora file.
     Start up the databse.

60. How can we specify the Archived log file name format and destination ?

By setting the following values in init.ora file.

LOG_ARCHIVE_FORMAT = arch %S/s/T/tarc (%S - Log sequence number and is zero left  paded,  %s  -  Log  sequence  number  not  padded. %T - Thread number lef-zero-paded  and  %t -  Thread number not padded). The file name created is arch 0001 are if %S is used.
LOG_ARCHIVE_DEST = path.

61. What is the use of  ANALYZE command  ?

To perform one of these function on an index,table, or cluster:

     -  to  collect statisties about object used by the optimizer and store them in the data           dictionary.
     -  to  delete statistics about the object used by object from the data dictionary.
     - to validate the structure of the object.
     - to identify migrated and chained rows of the table or cluster.

MANAGING DISTRIBUTED DATABASES.

62. How can we reduce the network traffic ?
     - Replictaion of data in distributed environment.
     - Using snapshots to replicate data.
     - Using remote procedure calls.

63. What is snapshots ?

Snapshot is an object used to dynamically replicate data between distribute database at specified  time intervals. In ver 7.0 they are read only.

64. What are the various type of snapshots ?

Simple and Complex.

65. Differentiate simple and complex, snapshots ?

     -  A  simple snapshot is based on a query that does not contains GROUP BY clauses, CONNECT BY clauses, JOINs, sub-query or snashot of operations.
     - A complex snapshots contain atleast any one of the above.

66. What dynamic data replication ?

Updating or Inserting records in remote database through database triggers. It may fail if remote database is having any problem.

67. How can you Enforce Refrencial Integrity  in snapshots ?

Time the references to occur when master tables are not in use.
 Peform the reference the manually immdiately locking the master tables. We  can join  tables in snopshots by creating a complex snapshots that will based on the master tables.

68. What are the options available to  refresh snapshots ?

COMPLETE   -   Tables   are  completly  regenerated  using  the  snapshot's query and the master tables every time the snapshot referenced.
FAST  - If simple snapshot used then a snapshot log can be used to send the changes to  the snapshot tables.
FORCE  -  Default value. If possible it performs a  FAST refresh; Otherwise it will perform a complete refresh.

69. what is snapshot log ?

It  is a table that maintains a record of modifications to the master table in  a  snapshot.  It is stored  in the same database as master table and is only  available for simple snapshots.  It should be created before creating snapshots.

70. When will the data in the snapshot log be used ?

We  must be able to create a after row trigger on table (i.e., it should be not be already available )

After giving table privileges.

We  cannot  specify  snapshot  log name because oracle uses the name of the master  table in the name of the database objects that support its snapshot log.

The master table name should be less than or equal to 23 characters.

(The  table  name created will be MLOGS_tablename, and trigger name will be TLOGS name).

72. What are the benefits of distributed options in databases ?

Database  on  other  servers  can  be updated and those transactions can be grouped together with others in a logical unit.
Database uses a two phase commit.

MANAGING BACKUP & RECOVERY

73. What are the different methods of backing up oracle database ?

     - Logical Backups
     - Cold Backups
     - Hot Backups (Archive log)

74. What is a logical backup ?

Logical  backup  involves reading a set of databse records and writing them into a file. Export utility is used for taking backup and Import utility is used to recover from backup.

75. What is cold backup ? What are the elements of it ?

Cold backup is taking backup of all physical files after normal shutdown of database.  We need to take.
     - All Data files.
     - All Control files.
     - All on-line redo log files.
     - The init.ora file (Optional)

76. What are the different kind of export backups ?

Full back      - Complete database
Incremental          - Only affected tables from last incremental date/full backup date.
Cumulative  backup - Only affected table from the last cumulative date/full backup date.

77. What is hot backup and how it can be taken ?

Taking  backup  of  archive  log  files when database is open. For this the ARCHIVELOG  mode  should  be enabled. The following files need to be backed up.
All data files. All  Archive log, redo log files. All control files.

78. What is the use of FILE option in EXP command ?

To give the export file name.

79. What is the use of COMPRESS option in EXP command ?

Flag  to  indicate  whether export should compress fragmented segments into single extents.

80. What is the use of GRANT option in EXP command ?

A  flag  to  indicate whether grants on databse objects will be exported or not. Value is 'Y'  or 'N'.

81. What is the use of INDEXES option in EXP command ?

A flag to indicate whether indexes on tables will be exported.

82. What is the use of ROWS option in EXP command ?

Flag  to  indicate  whether  table rows should be exported. If 'N' only DDL statements for the databse objects will be created.

83. What is the use of CONSTRAINTS option in EXP command ?

A flag to indicate whether constraints on table need to be exported.

84. What is the use of FULL option in EXP command ?

A flag to indicate whether full databse export should be performed.

85. What is the use of OWNER option in EXP command ?
List of table accounts should be exported.

86. What is the use of TABLES option in EXP command ?

List of tables should be exported.

87. What is the use of RECORD LENGTH option in EXP command ?

Record length in bytes.

88. What is the use of INCTYPE option in EXP command ?

Type export should be performed COMPLETE,CUMULATIVE,INCREMENTAL.

89. What is the use of RECORD option in EXP command ?

For Incremental exports, the flag indirects whether a record will be stores data dictionary tables recording the export.

90. What is the use of PARFILE option in EXP command ?

Name of the parameter file to be passed for export.

91. What is the use of PARFILE option in EXP command ?

Name of the parameter file to be passed for export.

92.  What is the use of ANALYSE ( Ver 7) option in  EXP command ?

A  flag  to  indicate  whether  statistical  information about the exported objects should be written to export dump file.

93.  What is the use of CONSISTENT (Ver 7) option in  EXP command ?

A  flag  to indicate whether  a read consistent version of all the exported objects should be maintained.


94.   What is use of LOG (Ver 7) option in  EXP command ?

The name of the file which log of the export will be written.

95.What is the use of FILE option in  IMP command ?

The name of the file from which import should be performed.

96.  What is the use of SHOW option in IMP command ?

A flag to indicate whether file content should be displayed or not.

97.  What is the use of IGNORE option in IMP command ?

A  flag  to indicate whether the import should ignore errors encounter when issuing CREATE commands.

98. What is the use of GRANT option in IMP command ?

A flag to indicate whether grants on database objects will be imported.

99. What is the use of INDEXES option in IMP command ?

A flag to indicate whether import should import index on tables or not.

100. What is the use of ROWS option in IMP command ?

A  flag  to indicate whether rows should be imported. If this is set to 'N' then only DDL for database  objects  will be exectued.






SQL PLUS STATEMENTS

1. 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.
Transactional Control : COMMIT & ROLLBACK
Session Control : ALTERSESSION & SET ROLE
System Control : ALTER SYSTEM.

2. What is a transaction ?

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

3. What is difference between TRUNCATE & DELETE ?

TRUNCATE commits after deleting entire table i.e., can not 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.

4. 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 retrive rows that do not have corresponding join value in the other table.

5. What is the  Subquery ?

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

6. What is correlated sub-query ?

Correlated sub_query is a sub_query which has reference to the main query.

7. Explain   Connect by Prior ?

Retrives rows in hierarchical order.
e.g. select empno, ename from emp where.

8. Difference between SUBSTR and INSTR ?

INSTR (String1,String2(n,(m)),
INSTR  returns  the  position  of  the  mth  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 nth postion of string1.

9. Explain UNION,MINUS,UNION ALL, 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.

10. What is ROWID ?

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

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

Using ROWID.

CONSTRAINTS

12. What is an Integrity  Constraint ?

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

13. What is Referential Integrity ?

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.

14. What are 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.

15.  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.

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

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

17.  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 it is 255 and 2000 for VARCHAR2.

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

19. What are the pre requisites  ?
     I. to modify datatype of a column ?
     ii. 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.

20. Where the integrity constrints are stored in Data Dictionary ?

The integrity constraints are stored in  USER_CONSTRAINTS.

21. How will you a activate/deactivate integrity constraints ?

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

22. If an 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.

23. What is a database link ?

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

24.  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.

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

CYCLE  specifies  that  the  sequence  continues  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.

26. 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.

27. 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.

28.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 which are base tables of a view will the changes be reference on the view.

PACKAGE PROCEDURE & FUNCTION

29. What is a Package Procedure ?

A Package proecdure is built in PL/SQL procedure.

30. What are the different types of Package Procedure ?

1. Restricted package procedure.
   2. Unrestricted package proecdure.

31.  What  is  the  difference  between restricted and unrestricted package procedure ?
Restricted  package procedure that affects the basic basic functions of SQL * Forms. It cannot used in all triggers execpt key triggers.

Unrestricted  package  procedure  that  does  not  interfere with the basic functions of SQL * Forms it can be used in any triggers.

32. Classify the restricted and unrestricted procedure from the following.
     a. Call
     b. User-Exit
     c. Call-Query
     d. Up
     e. Execute-Query
     f. Message
     g. Exit-From
     h. Post
     i. Break

a. Call - unrestricted
     b. User Exit - Unrestricted
     c. Call_query - Unrestricted
     d. Up - Restricted
     e. Execute Query - Restricted
     f. Message - Restricted
     g. Exit_form - Restricted
     h. Post - Restricted
     i. Break - Unrestricted.

33.  Can we use a restricted package procedure in ON-VALIDATE-FIELD Trigger ?

No.

34. What SYNCHRONIZE procedure does ?

It synchoronizes the terminal screen with the internal state of the form.

35.  What  are  the unrestricted procedures used to change the popup screen position during run time ?

Anchor-view
  Resize -View
 Move-View.

36. What Enter package procedure does ?

Enter Validate-data in the current validation unit.

37. What ERASE package procedure does ?

Erase removes an indicated global variable.

38. What is the difference between NAME_IN and COPY ?

Copy is package procedure and writes values into a field.
Name  in  is a package function and returns the contents of the variable to which you apply.

38. Identify package function from the following ?
     1. Error-Code
     2. Break
     3. Call
     4. Error-text
     5. Form-failure
     6. Form-fatal
     7. Execute-query
     8. Anchor_View
     9. Message_code


     1. Error_Code
     2. Error_Text
     3. Form_Failure
     4. Form_Fatal
     5. Message_Code

40. How does the command POST differs from COMMIT ?

Post writes  data in the form to the database but does not perform database commit
Commit permenently writes data in the form to the database.

41. What the PAUSE package procedure does ?

Pause suspends processing until the operator presses a function key

42. What package procedure is used for calling another form ?

Call  (E.g. Call(formname)

43. What package procedure used for invoke sql *plus from sql *forms ?

Host (E.g. Host (sqlplus))

44. Error_Code is a package proecdure ?
     a. True        b. false

False.

45. EXIT_FORM is a restricted package procedure ?
     a. True        b. False

True.

46.  When  the  form  is  running in DEBUG mode, If you want to examine the values of global variables and other form variables, What package procedure command you would use in your trigger text ?

Break.

SYSTEM VARIABLES

47. List the system variables related in Block and Field?


     1. System.block_status
     2. System.current_block
     3. System.current_field
     4. System.current_value
     5. System.cursor_block
     6. System.cursor_field
     7. System.field_status.

48.    What    is   the   difference   between   system.current_field   and system.cursor_field ?

1. System.current_field gives name of the field.
   2. System.cursor_field gives name of the field with block name.

49. The value recorded in system.last_record variable is of type
     a. Number
     b. Boolean
     c. Character.
b. Boolean.

User Exits :

50. What is an User Exits ?

A  user  exit  is  a  subroutine which are written in programming languages using pro*C pro *Cobol , etc., that link into the SQL * forms executable.

51. What are the type of  User Exits ?

ORACLE Precompliers user exits
OCI (ORACLE Call Interface)
Non-ORACEL user exits.

Page :

52. What do you mean by a page ?

Pages  are  collection  of  display  information, such as constant text and graphics.

53. How many pages you can in a single form ?

Unlimited.

54. Two popup pages can appear on the screen at a time ?
     a. True        b. False

     a. True.

55.What is the significance of PAGE 0 in forms 3.0 ?

Hide the fields for internal calculation.

56. Deleting a page removes information about all the fields in that page ?
     a. True.  b. False

a. True.

Popup Window :

57. What do you mean by a pop-up window ?

Pop-up  windows  are  screen  areas  that  overlay  all or a portion of the
display screen when a form is running.

58. What are the types of Pop-up window ?

the pop-up field editor
   pop-up list of values
   pop-up pages.

Alert :

59. What is an Alert ?

An  alert  is  window that appears in the middle of the screen overlaying a portion of the current display.



PL/SQL

Basiscs of PL/SQL

1. What is PL/SQL ?
PL/SQL  is  a  procedural  language  that  has  both  interactive  SQL  and procedural  programming  language constructs such as iteration, conditional branching.

2. What is the basic structure of PL/SQL ?

PL/SQL  uses  block  structure  as its basic structure. Anonymous blocks or nested blocks can be used in PL/SQL.

3. What are the components of a PL/SQL block ?

A set of related declarations and procedural statements is called block.

4. What are the components of a PL/SQL Block ?

Declarative part, Executable part and Execption part.

Datatypes PL/SQL

5. What are the datatypes a available in PL/SQL ?

Some  scalar  data  types  such  as NUMBER, VARCHAR2, DATE, CHAR, LONG, BOOLEAN.
Some composite data types such as RECORD & TABLE.

6.  What  are % TYPE and % ROWTYPE ? What are the advantages of using these over datatypes?

%  TYPE  provides  the data type of a variable or a database column to that variable.

% ROWTYPE  provides the record type that represents a entire row of a table or view or columns selected in the cursor.

The advantages are : I. Need not  know about variable's data type
ii.  If  the  database  definition of a column in a table changes, the data type of a variable changes accordingly.

7. What is difference between % ROWTYPE and TYPE RECORD ?

%  ROWTYPE  is to be used whenever query returns a entire row of a table or view.

TYPE  rec  RECORD is to be used whenever query returns columns of different
table or views and variables.

     E.g.  TYPE  r_emp is RECORD (eno emp.empno% type,ename emp ename %type
);
     e_rec emp% ROWTYPE
     cursor c1 is select empno,deptno from emp;
     e_rec c1 %ROWTYPE.

8. What is PL/SQL table ?

Objects  of  type  TABLE are called "PL/SQL  tables", which are modelled as (but  not the same as) database tables,  PL/SQL tables use a primary PL/SQL tables can have one column and a primary key.


Cursors

9. What is a cursor ? Why Cursor is required ?

Cursor is a named private SQL area from where information can be accessed. Cursors  are  required  to  process rows individually for queries returning multiple rows.

10. Explain the two type of Cursors ?

There are two types of cursors, Implict  Cursor and Explicit Cursor.
PL/SQL uses Implict Cursors for queries.
User  defined cursors are called Explicit Cursors. They can be declared and used.

11. What are the PL/SQL Statements used in cursor processing ?

DECLARE  CURSOR  cursor  name,  OPEN  cursor  name,  FETCH cursor name INTO  or Record types, CLOSE cursor name.

12. What are the cursor attributes used in PL/SQL ?

%ISOPEN  - to check whether cursor is open or not
   % ROWCOUNT - number of rows featched/updated/deleted.
   %  FOUND - to check whether cursor has fetched any row. True if rows are featched.
     % NOT FOUND - to check whether cursor has featched any row. True if no rows are featched.
These  attributes are proceded with SQL for Implict Cursors and with Cursor name for Explict Cursors.

13. What is a cursor for loop ?

Cursor  for loop implicitly declares %ROWTYPE as loop index,opens a cursor, fetches rows of values from active set into fields in the record and closes
when all the records have been processed.

     eg. FOR emp_rec IN C1 LOOP
          salary_total := salary_total +emp_rec sal;
          END LOOP;

14. What will happen after commit statement ?
          Cursor C1 is
          Select empno,
          ename from emp;
          Begin
               open C1;            loop
                    Fetch C1 into
               eno.ename;
                    Exit When
               C1 %notfound;-----
                    commit;
               end loop;
               end;

The  cursor  having  query  as  SELECT  ....  FOR  UPDATE gets closed after COMMIT/ROLLBACK.

The  cursor  having  query  as  SELECT....  does  not get closed even after COMMIT/ROLLBACK.

15. Explain the usage of  WHERE CURRENT OF clause in cursors ?

WHERE  CURRENT OF clause in an UPDATE,DELETE statement refers to the latest row fetched from a cursor.

Database Triggers

16. What is a database trigger ? Name some usages of database trigger ?

Database  trigger  is stored PL/SQL program unit associated with a specific database   table.   Usages   are  Audit  data  modificateions,  Log  events transparently,   Enforce   complex  business  rules  Derive  column  values automatically,   Implement   complex    security  authorizations.  Maintain replicate tables.

17.  How many types of database triggers can be specified on a table ? What are they ?

               Insert         Update          Delete

Before  Row    o.k.           o.k.            o.k.

After Row      o.k.           o.k.            o.k.

Before Statement    o.k.      o.k.            o.k.

After Statement     o.k.      o.k.            o.k.

If FOR EACH ROW clause is specified, then the trigger for each Row affected by the statement.

If  WHEN  clause  is specified, the trigger fires according to the retruned boolean value.

18. Is it possible to use Transaction control Statements such a ROLLBACK or COMMIT in Database Trigger ? Why ?

It  is  not  possible.  As  triggers are defined for each table, if you use COMMIT   of    ROLLBACK  in  a  trigger,  it  affects  logical  transaction processing.

19. What are two virtual tables available during database trigger execution ?

The table columns are referred as OLD.column_name and NEW.column_name.
For triggers related to INSERT only NEW.column_name values only available.
For  triggers related to UPDATE only OLD.column_name NEW.column_name values only available.
For triggers related to DELETE only OLD.column_name values only available.

20.  What happens if a procedure that updates a column of table X is called in a database trigger of the same table ?

Mutation of table occurs.

21.  Write  the  order  of precedence for validation of a column in a table ?
          I.  done using Database triggers.
          ii. done using Integarity Constraints.

I & ii.

Exception :

22. What is an Exception ? What are types of Exception ?

Exception  is  the  error  handling  part  of  PL/SQL  block. The types are Predefined and user_defined. Some of Predefined execptions are.
     CURSOR_ALREADY_OPEN
     DUP_VAL_ON_INDEX
     NO_DATA_FOUND
     TOO_MANY_ROWS
     INVALID_CURSOR
     INVALID_NUMBER
     LOGON_DENIED
     NOT_LOGGED_ON
     PROGRAM-ERROR
     STORAGE_ERROR
     TIMEOUT_ON_RESOURCE
     VALUE_ERROR
     ZERO_DIVIDE
     OTHERS.

23. What is Pragma EXECPTION_INIT ? Explain the usage ?

The PRAGMA EXECPTION_INIT tells the complier to associate an exception with an oracle error. To get an error message of a specific oracle error.

     e.g. PRAGMA EXCEPTION_INIT (exception name, oracle error number)

24. What is Raise_application_error ?

Raise_application_error  is  a  procedure  of  package  DBMS_STANDARD which allows  to  issue an user_defined error messages from stored sub-program or database trigger.

25. What are the return values of functions SQLCODE and SQLERRM ?

SQLCODE returns the latest code of the error that has occured.
SQLERRM returns the relevant error message of the SQLCODE.

26. Where the Pre_defined_exceptions are stored ?

In the standard package.

Procedures, Functions & Packages ;

27. What is a stored procedure ?

A  stored  procedure  is  a  sequence  of  statements that perform specific function.

28. What is difference between a PROCEDURE & FUNCTION ?

A FUNCTION is alway returns a value using the return statement.
        A  PROCEDURE   may  return one or more values through parameters or may not return at all.

29. What are advantages fo Stored Procedures /

Extensibility,Modularity,   Reusability,   Maintainability   and  one  time compilation.

30. What are the modes of parameters that can be passed to a procedure ?

IN,OUT,IN-OUT parameters.

31. What are the two parts of a procedure ?

Procedure Specification and Procedure Body.

32. Give the structure of the procedure ?


     PROCEDURE name (parameter list.....)
     is
     local variable declarations

     BEGIN
          Executable statements.
     Exception.
     exception handlers

     end;

33. Give the structure of the function ?


     FUNCTION name (argument list .....) Return datatype is
     local variable declarations
     Begin
          executable statements
     Exception
          execution handlers
     End;

34. Explain how procedures and functions are called in a PL/SQL block ?

Function is called as part of an expression.
   sal := calculate_sal ('a822');
   procedure is called as a PL/SQL statement
   calculate_bonus ('A822');

35. What is Overloading of procedures ?

The  Same procedure name is repeated with parameters of different datatypes and  parameters  in  different  positions,  varying number of parameters is called overloading of procedures.

e.g. DBMS_OUTPUT put_line

36. What is a package ? What are the advantages of packages ?

Package is a database object that groups logically related procedures.
The  advantages  of  packages  are  Modularity,  Easier  Applicaton Design, Information. Hiding,. reusability and Better Performance.

37.What are two parts of package ?

The two parts of package are PACKAGE SPECIFICATION & PACKAGE BODY.

Package Specification contains declarations that are global to the packages and local to the schema.
Package  Body  contains  actual  procedures  and  local  declaration of the procedures and cursor declarations.

38.  What is difference between a Cursor declared in a procedure and Cursor declared in a package specification ?

A  cursor declared in a package specification is global and can be accessed by other procedures or procedures in a package.
A  cursor declared in a procedure is local to the procedure that can not be accessed by other procedures.

39. How packaged procedures and functions are called from the following?
     a. Stored procedure or anonymous block
     b. an application program such a PRC *C, PRO* COBOL
     c. SQL *PLUS

     a. PACKAGE NAME.PROCEDURE NAME (parameters);
        variable := PACKAGE NAME.FUNCTION NAME (arguments);
        EXEC SQL EXECUTE
     b.
          BEGIN
               PACKAGE NAME.PROCEDURE NAME (parameters)
               variable := PACKAGE NAME.FUNCTION NAME      (arguments);
          END;
          END EXEC;
     c.  EXECUTE PACKAGE NAME.PROCEDURE if the procedures does not have any
out/in-out parameters. A function can not be called.

40.  Name  the  tables  where  characteristics  of  Package,  procedure and functions are stored ?

User_objects, User_Source and User_error.


Oracle DBA

1. SNAPSHOT is used for
    [DBA]  a]  Synonym,  b]  Table space, c] System server, d] Dynamic data
replication

Ans : D

2. We can create SNAPSHOTLOG for
    [DBA]      a] Simple snapshots, b] Complex snapshots, c] Both A & B, d]
Neither A nor B

Ans : A

3. Transactions per rollback  segment is derived from
    [DBA]  a]  Db_Block_Buffers, b] Processes, c] Shared_Pool_Size, d] None
of the above

Ans : B


4. ENQUEUE resources parameter information is derived from
    [DBA]      a] Processes or DDL_LOCKS and DML_LOCKS, b] LOG_BUFFER,
          c] DB__BLOCK_SIZE..
Ans : A

5. LGWR process writes information into
          a] Database files, b] Control files, c] Redolog files, d] All the
above.
Ans : C

6.  SET  TRANSACTION USE ROLLBACK SEGMENT  is used to create user
objects
    in a particular Tablespace
          a] True, b] False
Ans : False

7. Databases overall structure is maintained in a file called
          a]  Redolog  file,  b]  Data file, c] Control file, d] All of the
above.
Ans : C

8.  These  following  parameters  are  optional  in init.ora parameter file
DB_BLOCK_SIZE,
    PROCESSES
          a] True, b] False
Ans : False

9. Constraints cannot be exported through EXPORT  command
          a] True, b] False
Ans : False

10.  It  is  very difficult to grant and manage common privileges needed by
different groups of
      database users using the roles
          a] True, b] False
Ans : False



11.  What  is  difference  between  a  DIALOG  WINDOW and a DOCUMENT WINDOW
regarding
      moving the window with respect to the application window
     a]  Both  windows  behave  the same way as far as moving the window is
concerned.
     b] A document window can be moved outside the application window while
a dialog
         window cannot be moved
     c] A dialog window can be moved outside the application window while a
document
         window cannot be moved
Ans : C

12. What is the difference between a MESSAGEBOX and an ALERT
     a]  A  messagebox can be used only by the system and cannot be used in
user application
         while an alert can be used in user application also.
     b]  A  alert can be used only by the system and cannot be use din user
application
         while an messagebox  can be used in user application also.
     c]  An alert requires an response from the userwhile a messagebox just
flashes a message
         and only requires an acknowledment from the user
     d] An message box requires an response from the userwhile a alert just
flashes a
                message an only requires an acknowledment from the user
Ans : C

13.  Which  of the following is not an reason for the fact that most of the
processing is done at the
      server ?
     a]  To  reduce  network  traffic.  b]  For  application sharing, c] To
implement business rules
                centrally, d] None of the above
Ans : D

14. Can a DIALOG WINDOW have scroll bar attached to it ?
     a] Yes, b] No
Ans : B

15. Which of the following is not an advantage of GUI systems ?
     a]  Intuitive  and  easy  to  use.,  b]  GUI's  can  display  multiple
applications in multiple windows
     c] GUI's provide more user interface objects for a developer
     d] None of the above
Ans :D

16. What is the difference between a LIST BOX and a COMBO BOX ?
     a] In the list box, the user is restricted to selecting a value from a
list but in a combo box
         the user can type in a value which is not in the list
     b]  A list box is a data entry area while a combo box can be used only
for control purposes
     c]  In a combo box, the user is restricted to selecting a value from a
list but in a list box the
         user can type in a value which is not in the list
     d] None of the above
Ans : A

17.  In  a  CLIENT/SERVER environment , which of the following would not be
done at the client ?
     a]  User  interface  part,  b]  Data  validation  at  entry  line,  c]
Responding to user events,
     d] None of the above
Ans : D

18.  Why  is it better to use an INTEGRITY CONSTRAINT to validate data in a
table than to use a
      STORED PROCEDURE ?
     a] Because an integrity constraint is automatically checked while data
is inserted into or
                updated  in  a  table  while  a  stored procedure has to be
specifically invoked
     b]  Because  the  stored procedure occupies more space in the database
than a integrity
         constraint definition
     c]  Because  a  stored  procedure  creates more network traffic than a
integrity constraint
         definition
Ans : A

19. Which of the following is not an advantage of a client/server model ?
     a]  A  client/server  model  allows  centralised  control  of data and
centralised implementation
         of business rules.
     b] A client/server model increases developer;s productivity
     c] A client/server model is suitable for all applications
     d] None of the above.
Ans : C

20. What does DLL stands for ?
     a] Dynamic Language Library
     b] Dynamic Link Library
     c] Dynamic Load Library
     d] None of the above
Ans : B

21. POST-BLOCK trigger is a
     a] Navigational trigger
     b] Key trigger
     c] Transactional trigger
     d] None of the above
Ans : A

22.  The system variable that records the select statement that SQL * FORMS
most recently used
      to populate a block is
     a] SYSTEM.LAST_RECORD
     b] SYSTEM.CURSOR_RECORD
     c] SYSTEM.CURSOR_FIELD
     d] SYSTEM.LAST_QUERY
Ans: D

23. Which of the following is TRUE for the ENFORCE KEY field
     a]  ENFORCE  KEY field characteristic indicates the source of the value
that SQL*FORMS
                uses to populate the field
     b]  A  field  with the ENFORCE KEY characteristic should have the INPUT
ALLOWED
                characteristic turned off
     a] Only 1 is TRUE
     b] Only 2 is TRUE
     c] Both 1 and 2 are TRUE
     d] Both 1 and 2 are FALSE
Ans : A

24. What is the maximum size of the page ?
     a] Characters wide & 265 characters length
     b] Characters wide & 265 characters length
     c] Characters wide & 80 characters length
     d] None of the above
Ans : B

25. A FORM is madeup of which of the following objects
     a] block, fields only,
     b] blocks, fields, pages only,
     c] blocks, fields, pages, triggers and form level procedures,
     d] Only blocks.
Ans : C

26. For the following statements which is true
     1] Page is an object owned by a form
     2] Pages are a collection of display information such as constant text
and graphics.
          a] Only 1 is TRUE
          b] Only 2 is TRUE
          c] Both 1 & 2 are TRUE
          d] Both are FALSE
Ans : B

27.  The  packaged  procedure  that  makes  data  in  form permanent in the Database is
     a] Post
     b] Post form
     c] Commit form
     d] None of the above
Ans : C

28. Which of the following is TRUE for the SYSTEM VARIABLE $$date$$
     a] Can be assigned to a global variable
     b] Can be assigned to any field only during design time
     c] Can be assigned to any variable or field during run time
     d] None of the above
Ans : B

29. Which of the following packaged procedure is UNRESTRICTED ?
     a] CALL_INPUT, b] CLEAR_BLOCK, c] EXECUTE_QUERY, d] USER_EXIT
Ans : D

30. Identify the RESTRICTED packaged procedure from the following
     a] USER_EXIT, b] MESSAGE, c] BREAK, d] EXIT_FORM
Ans : D

31. What is SQL*FORMS
     a]  SQL*FORMS  is  a  4GL tool for developing & executing Oracle based
interactive
                applications.
     b] SQL*FORMS is a 3GL tool for connecting to the Database.
     c] SQL*FORMS is a reporting tool
     d] None of the above.
Ans : A

32.  Name  the  two  files  that are created when you generate a form using
Forms 3.0
     a] FMB & FMX, b] FMR & FDX, c] INP & FRM, d] None of the above
Ans : C





33. What is a trigger
     a] A piece of logic written in PL/SQL
     b] Executed at the arrival of a SQL*FORMS event
     c] Both A & B
     d] None of the above
Ans : C

34. Which of the folowing is TRUE for a ERASE packaged procedure
     1]  ERASE  removes  an indicated Global variable & releases the memory
associated with it
     2] ERASE is used to remove a field from a page
          1] Only 1 is TRUE
          2] Only 2 is TRUE
          3] Both 1 & 2 are TRUE
          4] Both 1 & 2 are FALSE
Ans : 1

35.  All  datafiles related to a Tablespace are removed when the Tablespace
is dropped
     a] TRUE
     b] FALSE
Ans : B

36. Size of Tablespace can be increased by
     a] Increasing the size of one of the Datafiles
     b] Adding one or more Datafiles
     c] Cannot be increased
     d] None of the above
Ans : B

37. Multiple Tablespaces can share a single datafile
     a] TRUE
     b] FALSE
Ans : B

38. A set of Dictionary tables are created
     a] Once for the Entire Database
     b] Every time a user is created
     c] Every time a Tablespace is created
     d] None of the above
Ans : A

39. Datadictionary can span across multiple Tablespaces
     a] TRUE
     b] FALSE
Ans : B


40.  What is a DATABLOCK
     a] Set of Extents
     b] Set of Segments
     c] Smallest Database storage unit
     d] None of the above
Ans : C


41.  Can  an  Integrity  Constraint be enforced on a table if some existing
table data does not satisfy
      the constraint
     a] Yes
     b] No
Ans : B

42. A column defined as PRIMARY KEY can have NULL's
     a] TRUE
     b] FALSE
Ans : B

43. A Transaction ends
     a] Only when it is Committed
     b] Only when it is Rolledback
     c] When it is Committed or Rolledback
     d] None of the above
Ans : C

44. A Database Procedure is stored in the Database
     a] In compiled form
     b] As source code
     c] Both A & B
     d] Not stored
Ans : C

45.  A  database trigger doesnot apply to data loaded before the definition
of the trigger
     a] TRUE
     b] FALSE
Ans : A

46. Dedicated server configuration is
     a] One server process - Many user processes
     b] Many server processes - One user process
     c] One server process - One user process
     d] Many server processes - Many user processes
Ans : C

47. Which of the following does not affect the size of the SGA
     a] Database buffer
     b] Redolog buffer
     c] Stored procedure
     d] Shared pool
Ans : C

48. What does a COMMIT statement do to a CURSOR
     a] Open the Cursor
     b] Fetch the Cursor
     c] Close the Cursor
     d] None of the above
Ans : D




49. Which of the following is TRUE
     1]    Host variables are declared anywhere in the program
     2]   Host variables are declared in the DECLARE section
          a] Only 1 is TRUE
          b] Only 2 is TRUE
          c] Both 1 & 2are TRUE
          d] Both are FALSE
Ans : B

50. Which of the following is NOT VALID is PL/SQL
     a] Bool boolean;
     b] NUM1, NUM2 number;
     c] deptname dept.dname%type;
     d] date1 date := sysdate
Ans : B

51. Declare
     fvar number := null; svar number := 5
      Begin
     goto << fproc>>
     if fvar is null then
          << fproc>>
          svar := svar + 5
     end if;
       End;

What will be the value of svar after the execution ?
     a] Error
     b] 10
     c] 5
     d] None of the above

Ans : A

52. Which of the following is not correct about an Exception ?
     a] Raised automatically / Explicitly in response to an ORACLE_ERROR
     b] An exception will be raised when an error occurs in that block
     c] Process terminates after completion of error sequence.
     d] A Procedure or Sequence of statements may be processed.

Ans : C

53. Which of the following is not correct about User_Defined Exceptions ?
     a] Must be declared
     b] Must be raised explicitly
     c] Raised automatically in response to an Oracle error
     d] None of the above

Ans : C





54. A Stored Procedure is a
     a] Sequence of SQL or PL/SQL statements to perform specific function
     b] Stored in compiled form in the database
     c] Can be called from all client environmets
     d] All of the above

Ans : D

55. Which of the following statement is false
     a]  Any  procedure  can  raise an error and return an user message and
error number
     b]  Error  number  ranging  from  20000 to 20999 are reserved for user
defined messages
     c] Oracle checks Uniqueness of User defined errors
     d] Raise_Application_error is used for raising an user defined error.

Ans : C

56.  Is  it  possible  to  open  a  cursor which is in a Package in another
procedure ?
     a] Yes
     b] No

Ans : A

57.  Is  it  possible  to  use Transactional control statements in Database
Triggers ?
     a] Yes
     b] No

Ans : B

58. Is it possible to Enable or Disable a Database trigger ?
     a] Yes
     b] No

Ans : A

59. PL/SQL supports datatype(s)
     a] Scalar datatype
     b] Composite datatype
     c] All of the above
     d] None of the above

Ans C

60. Find the ODD datatype out
     a] VARCHAR2
     b] RECORD
     c] BOOLEAN
     d] RAW

Ans : B





61. Which of the following is not correct about the "TABLE" datatype ?
     a] Can contain any no of columns
     b] Simulates a One-dimensional array of unlimited size
     c] Column datatype of any Scalar type
     d] None of the above

Ans : A

62. Find the ODD one out of the following
     a] OPEN
     b] CLOSE
     c] INSERT
     d] FETCH

Ans C

63. Which of the following is not correct about Cursor ?
     a] Cursor is a named Private SQL area
     b] Cursor holds temporary results
     c] Cursor is used for retrieving multiple rows
     d] SQL uses implicit Cursors to retrieve rows

Ans : B

64. Which of the following is NOT VALID in PL/SQL ?
     a] Select ... into
     b] Update
     c] Create
     d] Delete

Ans : C

65. What is the Result of the following  'VIK'||NULL||'RAM' ?
     a] Error
     b] VIK RAM
     c] VIKRAM
     d] NULL

Ans : C

66. Declare
     a number := 5; b number := null; c number := 10;
     Begin
          if a > b AND a < c then
               a := c * a;
          end if;
     End;
What will be the value of 'a' after execution ?
     a] 50
     b] NULL
     c] 5
     d] None of the above

Ans : C
67. Does the Database trigger will fire when the table is TRUNCATED ?
     a] Yes
     b] No

Ans : B

68. SUBSTR(SQUARE ANS ALWAYS WORK HARD,14,6) will return
     a] ALWAY
     b} S ALWA
     c] ALWAYS
Ans : C

69. REPLACE('JACK AND JUE','J','BL') will return
     a] JACK AND BLUE
     b] BLACK AND JACK
     c] BLACK AND BLUE
     d] None of the above

Ans : C

70. TRANSLATE('333SQD234','0123456789ABCDPQRST','0123456789') will return
     a] 333234
     b] 333333
     c] 234333
     d] None of the above

Ans : A

71.  EMPNO     ENAME               SAL
     A822      RAMASWAMY      3500
     A812      NARAYAN        5000
     A973      UMESH               2850
     A500      BALAJI              5750

Use these data for the following Questions

     Select SAL from EMP E1 where 3 > ( Select count(*) from Emp E2
                                  where E1.SAL > E2.SAL ) will retrieve
     a] 3500,5000,2500
     b] 5000,2850
     c] 2850,5750
     d] 5000,5750

Ans : A

72. Is it possible to modify a Datatype of a column when column contains
data ?
     a] Yes
     b] No

Ans B




73. Which of the following is not correct about a View ?
     a] To protect some of the columns of a table from other users
     b] Ocuupies data storage space
     c] To hide complexity of a query
     d] To hide complexity of a calculations

Ans : B

74. Which is not part of the Data Definiton Language ?
     a] CREATE
     b] ALTER
     c] ALTER SESSION


Ans : C

75. The Data Manipulation Language statements are
     a] INSERT
     b] UPDATE
     c] SELECT
     d] All of the above

Ans : D

76.  EMPNO     ENAME               SAL
     A822      RAMASWAMY      3500
     A812      NARAYAN        5000
     A973      UMESH
     A500      BALAJI              5750

     Using the above data
     Select count(sal) from Emp will retrieve
     a] 1
     b] 0
     c] 3
     d] None of the above

Ans : C

77. If an UNIQUE KEY constraint on DATE column is created, will it accept
the rows that are
     inserted with SYSDATE ?
     a] Will
     b] Won't

Ans : B


78. What are the different events in Triggers ?
     a] Define, Create
     b] Drop, Comment
     c] Insert, Update, Delete
     d] All of the above

Ans : C
79. What built-in subprogram is used to manipulate images in image items ?
     a] Zoom_out
     b] Zoom_in'
     c] Image_zoom
     d] Zoom_image

Ans : C

80. Can we pass RECORD GROUP between FORMS ?
     a] Yes
     b] No

Ans : A

81. SHOW_ALERT function returns
     a] Boolean
     b] Number
     c] Character
     d] None of the above

Ans : B

82. What SYSTEM VARIABLE  is used to refer DATABASE TIME ?
     a] $$dbtime$$
     b] $$time$$
     c] $$datetime$$
     d] None of the above

Ans : A

83. :SYSTEM.EFFECTIVE.DATE varaible is
     a] Read only
     b] Read & Write
     c] Write only
     d] None of the above

Ans : C

84. How can you CALL Reports from Forms4.0 ?
     a] Run_Report built_in
     b] Call_Report built_in
     c] Run_Product built_in
     d] Call_Product built_in

Ans : C

85. When do you get a .PLL extension ?
     a] Save Library file
     b] Generate Library file
     c] Run Library file
     d] None of the above

Ans : A

86. What is built_in Subprogram ?
     a] Stored procedure & Function
     b] Collection of Subprogram
     c] Collection of Packages
     d] None of the above

Ans : D

87. GET_BLOCK property is a
     a] Restricted procedure
     b] Unrestricted procedure
     c] Library function
     d] None of the above

Ans : D

88. A CONTROL BLOCK can sometimes refer to a BASETABLE  ?
     a] TRUE
     b] FALSE

Ans : B

89. What do you mean by CHECK BOX ?
     a] Two state control
     b] One state control
     c] Three state control
     d] none of the above

Ans  :  C - Please check the Correcness of this Answer ( The correct answer
is 2 )

90. List of Values (LOV) supports
     a] Single column
     b] Multi column
     c] Single or Multi column
     d] None of the above

Ans : C

91. What is Library in Forms 4.0 ?
     a] Collection of External field
     b] Collection of built_in packages
     c] Collection of PL/SQl functions, procedures and packages
     d] Collection of PL/SQL procedures & triggers

Ans : C

92. Can we use a RESTRICTED packaged procedure in WHEN_TEXT_ITEM trigger ?
     a] Yes
     b] No

Ans : B



93. Can we use GO_BLOCK package in a PRE_TEXT_ITEM trigger ?
     a] Yes
     b] No

Ans : B

94. What type of file is used for porting Forms 4.5 applications to various
platforms ?
     a] .FMB file
     b] .FMX file
     c] .FMT file
     d] .EXE file

Ans : C

95. What built_in procedure is used to get IMAGES in Forms 4.5 ?
     a] READ_IMAGE_FILE
     b] GET_IMAGE_FILE
     c] READ_FILE
     d] GET_FILE

Ans A

96.  When  a  form  is  invoked  with  CALL_FORM  does  Oracle forms issues
SAVEPOINT ?
     a] Yes
     b] No

Ans : A

97. Can we attach the same LOV to different fields in Design time ?
     a] Yes
     b] No

Ans : A

98. How do you pass values from one form to another form ?
     a] LOV
     b] Parameters
     c] Local variables
     d] None of the above

Ans : B

99. Can you copy the PROGRAM UNIT   into an Object group ?
     a] Yes
     b] No

Ans : B

100. Can MULTIPLE DOCUMENT INTERFACE (MDI) be used in Forms 4.5 ?
     a] Yes
     b] No

Ans : A

101. When is a .FMB file extension is created in Forms 4.5 ?
     a] Generating form
     b] Executing form
     c] Save form
     d] Run form

Ans : C

102. What is a Built_in subprogram ?
     a] Library
     b] Stored procedure & Function
     c] Collection of Subprograms
     d] None of the above

Ans : D

103. What is a RADIO GROUP ?
     a] Mutually exclusive
     b] Select more than one column
     c] Above all TRUE
     d] Above all FALSE

Ans : A

104. Identify the Odd one of the following statements ?
     a] Poplist
     b] Tlist
     c] List of values
     d] Combo box

Ans : C

105. What is an ALERT ?
     a] Modeless window
     b] Modal window
     c] Both are TRUE
     d] None of the above

Ans : B

106. Can an Alert message be changed at runtime ?
     a] Yes
     b] No

Ans : A

107. Can we create an LOV without an RECORD GROUP ?
     a} Yes
     b] No

Ans : B



108. How many no of columns can a RECORD GROUP have ?
     a] 10
     b] 20
     c] 50
     d] None of the above

Ans D

109. Oracle precompiler translates the EMBEDDED SQL statemens into
     a] Oracle FORMS
     b] Oracle REPORTS
     c] Oracle LIBRARY
     d] None of the above

Ans : D

110. Kind of COMMENT statements placed within SQL statements ?
     a] Asterisk(*) in column ?
     b] ANSI SQL style statements(...)
     c] C-Style comments (/*......*/)
     d] All the above

Ans : D

111.  What  is  the  appropriate  destination  type to send the output to a
printer ?
     a] Screen
     b] Previewer
     c] Either of the above
     d] None of the above

Ans : D

112. What is TERM ?
     a]  TERM  is  the terminal definition file that describes the terminal
from which you are
         using R20RUN ( Reports run time )
     b]  TERM  is  the terminal definition file that describes the terminal
from which you are
         using R20DES ( Reports designer )
     c] There is no Parameter called TERM in Reports 2.0
     d] None of the above

Ans : A

113.  If  the  maximum  records retrieved property of a query is set to 10,
then a summary value will
       be calculated
     a] Only for 10 records
     b] For all the records retrieved
     c] For all therecords in the referenced table
     d] None of the above

Ans : A


114.  With  which  function  of  a  summary  item  in the COMPUTE AT option
required ?
     a] Sum
     b] Standard deviation
     c] Variance
     d] % of Total function

Ans : D

115.  For  a  field in a repeating frame, can the source come from a column
which does not exist in
       the datagroup which forms the base of the frame ?
     a] Yes
     b] No

Ans : A

116.  What  are  the  different  file extensions that are created by Oracle
Reports ?
     a] .RDF file & .RPX file
     b] .RDX file & .RDF file
     c] .REP file & .RDF file
     d] None of the above

Ans : C

117.  Is it possible to Disable the Parameter form while running the report
?
     a] Yes
     b] No

Ans : A

118.What are the SQL clauses supported in the link property sheet ?
     a] WHERE & START WITH
     b] WHERE & HAVING
     c} START WITH & HAVING
     d] WHERE, START WITH & HAVING

Ans : D

119. What are the types of Calculated columns available ?
     a] Summary, Place holder & Procedure column
     b] Summary, Procedure & Formula columns
     c] Procedure, Formula & Place holder columns
     d] Summary, Formula & Place holder columns

Ans.: D

120.  If  two  groups  are not linked in the data model editor, what is the
hierarchy between them?
     a] There is no hierarchy between unlinked groups
     b]  The group that is right ranks higher than the group that is to the
left
     c]  The  group  that  is above or leftmost ranks higher than the group
that is to right or below
         it
     d] None of the above

Ans : C

121. Sequence of events takes place while starting a Database is
     a] Database opened, File mounted, Instance started
     b] Instance started, Database mounted & Database opened
     c] Database opened, Instance started & file mounted
     d] Files mounted, Instance started & Database opened

Ans : B

122. SYSTEM TABLESPACE can be made off-line
     a] Yes
     b] No

Ans : B

123. ENQUEUE_RESOURCES parameter information is derived from
     a] PROCESS or DDL_LOCKS & DML_LOCKS
     b] LOG BUFFER
     c] DB_BLOCK_SIZE
     d] DB_BLOCK_BUFFERS

Ans : A

124. SMON process is used to write into LOG files
     a] TRUE
     b] FALSE

Ans : B

125. EXP command is used
     a] To take Backup of the Oracle Database
     b] To import data from the exported dump file
     c] To create Rollback segments
     d] None of the above

Ans : A

126. SNAPSHOTS cannot be refreshed automatically
     a] TRUE
     b] FALSE
Ans : B
127. The User can set Archive file name formats
     a] TRUE
     b] FALSE

Ans : A

128.  The  following  parameters  are  optional  in init.ora parameter file
DB_BLOCK_SIZE,
        PROCESS
     a} TRUE
     b] FALSE

Ans : B
129.  NOARCHIEVELOG  parameter  is  used to enable the database in Archieve
mode
     a] TRUE
     b] FALSE

Ans : B

130. Constraints cannot be exported through Export command?
     a] TRUE
     b] FALSE

Ans : B

131.  It  is very difficult to grant and manage common priveleges needed by
different groups of
        database users using roles
     a] TRUE
     b] FALSE

Ans : B

132. The status of the Rollback segment can be viewed through
     a] DBA_SEGMENTS
     b] DBA_ROLES
     c] DBA_FREE_SPACES
     d] DBA_ROLLBACK_SEG

Ans : D

133. Explicitly we can assign transaction to a rollback segment
     a] TRUE
     B] FALSE

Ans : A

134. What file is read by ODBC to load drivers ?
     a] ODBC.INI
     b] ODBC.DLL
     c] ODBCDRV.INI
     d] None of the above

Ans : A