Oracle DBA Interview Questions

Oracle DBA Interview Questions

1. What is Log Switch?

Ans. The point at which ORACLE ends writing to one online redo log file and begins writing to another is called a log switch.

2. What is On-line Redo Log?

 Ans. The On-line Redo Log is a set of two 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.

3. Which parameter specified in the DEFAULT STORAGE clause of CREATE TABLESPACE cannot be altered after creating the tablespace?

 Ans. All the default storage parameters defined for the tablespace can be changed using the ALTER TABLESPACE command. When objects are created their INITIAL and MINEXTENS values cannot be changed.

4. What are the steps involved in Database Startup?

 Ans. Start an instance, Mount the Database and Open the Database.

5. What are the steps involved in Instance Recovery?

Ans. Rolling 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.

6. Can Full Backup be performed when the database is open?

Ans. No.

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

Ans. 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.

8. What are the advantages of operating a database in ARCHIVELOG mode over operating it in NO ARCHIVELOG mode?

Ans. Complete database recovery from disk failure is possible only in ARCHIVELOG mode. Online database backup is possible only in ARCHIVELOG mode.

9. What are the steps involved in Database Shutdown?

Ans. Close the Database, Dismount the Database and Shutdown the Instance.

10. What is Archived Redo Log?

Ans. Archived Redo Log consists of Redo Log files that have archived before being reused.

11. What is Restricted Mode of Instance Startup?

Ans. 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.

12. What is Partial Backup?

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

13. What is Mirrored on-line Redo Log?

Ans. 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.

14. What is Full Back up?

Ans. 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.

15. Can a View based on another View?

Ans. Yes.

16. Can a Tablespace hold objects from different Schemes?

Ans. Yes.

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

Ans. Yes.

18. What is the use of Control File?

Ans. 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.

19. Do View contain Data?

Ans. Views do not contain or store data.

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

Ans. 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.

21. What are the type of Synonyms?

Ans. There are two types of Synonyms Private and Public

22. What is a Redo Log?

Ans. The set of Redo Log files YSDATE, UID, USER or USERENV SQL functions, or the pseudo columns LEVEL or ROWNUM.

23. What is an Index Segment?

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

24. Explain the relationship among Database, Tablespace and Data file?

Ans. Each databases logically divided into one or more tablespaces one or more data files are explicitly created for each tablespace

25. What are the different type of Segments?

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

26. What are Clusters?

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

27. What is an Integrity Constrains?

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

28. What is an Index?

Ans. 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.

29. What is an Extent?

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

30. What is a View?

Ans. 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.)

31. What is Table?

Ans. 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.

32. What is a Synonym?

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

33. What is a Sequence?

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

34. What is a Segment?

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

35. What is schema?

Ans. A schema is collection of database objects of a User.

36. Describe Referential Integrity?

Ans. 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.

37. What is Hash Cluster?

Ans. 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.

38. What is a Private Synonyms?

Ans. A Private Synonyms can be accessed only by the owner.

39. What is Database Link?

Ans. A database link is a named object that describes a “path” from one database to another.

40. What is a Tablespace?

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

41. What is Rollback Segment?

Ans. A Database contains one or more Rollback Segments to temporarily store “undo” information.

42. What are the Characteristics of Data Files?

Ans. 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 tablespace.

43. How to define Data Block size?

Ans. 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 can’t be changed latter.

44. What does a Control file Contain?

Ans. 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.

45. What is difference between UNIQUE constraint and PRIMARY KEY constraint?

Ans. A column defined as UNIQUE can contain Nulls while a column defined as PRIMARY KEY can’t contain Nulls.

46. What is the effect of setting the value “ALL_ROWS” for OPTIMIZER_GOAL parameter of the ALTER SESSION command? What are the factors that affect OPTIMIZER in choosing an Optimization approach?

Ans. The OPTIMIZER_MODE initialization parameter Statistics in the Data Dictionary the OPTIMIZER_GOAL parameter of the ALTER SESSION command hints in the statement.

47. What is the effect of setting the value “CHOOSE” for OPTIMIZER_GOAL, parameter of the ALTER SESSION Command?

Ans. 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.

48. What is the function of Optimizer?

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

49. What is Execution Plan?

Ans. The combinations of the steps the optimizer chooses to execute a statement is called an execution plan.

50. What are the different approaches used by Optimizer in choosing an execution plan?

Ans. Rule-based and Cost-based.

51. What does ROLLBACK do?

Ans. ROLLBACK retracts any of the changes resulting from the SQL statements in the transaction.

52. What is SAVE POINT?

Ans. 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.

53. What are the values that can be specified for OPTIMIZER MODE Parameter?

Ans. COST and RULE.

54. What is COST-based approach to optimization?

Ans. 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.

55. What does COMMIT do?

Ans. 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.

56. What is RULE-based approach to optimization?

Ans. Choosing an executing plan based on the access paths available and the ranks of these access paths.

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

Ans. CHOOSE,ALL_ROWS,FIRST_ROWS and RULE.

58. Define Transaction?

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

59. What is Read-Only Transaction?

Ans. A Read-Only transaction ensures that the results of each query executed in the transaction are consistent with respect to the same point in time.

60. What is a deadlock?

Ans. Explain. Two processes waiting 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.

61. What is a Schema?

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

62. What is a cluster Key?

Ans. 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.

63. What is Parallel Server?

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

64. What are the basic element of Base configuration of an oracle Database?

Ans. 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

65. What is clusters?

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

66. What is an Index? How it is implemented in Oracle Database?

Ans. An index is a database structure used by the server to have direct access of a row in a table. An index is automatically created when a unique of primary key constraint clause is specified in create table command (Ver 7.0)

67. What is a Database instance?

Ans. 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.

68. What is the use of ANALYZE command?

Ans.

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

To collect statistics 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 off the table or cluster.

69. What is default tablespace?

Ans. The Tablespace to contain schema objects created without specifying a tablespace name.

70. What are the system resources that can be controlled through Profile?

Ans. 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 amount 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.

71. What is Tablespace Quota?

Ans. The collective amount of disk space available to the objects in a schema on a particular tablespace.

72. What are the different Levels of Auditing?

Ans. Statement Auditing, Privilege Auditing and Object Auditing.

73. What is Statement Auditing?

Ans. Statement auditing is the auditing of the powerful system privileges without regard to specifically named objects

74. What are the database administrator’s utilities available?

Ans. 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.

75. How can you enable automatic archiving?

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

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

Ans. Roles are the easiest way to grant and manage common privileges needed by different groups of database users. Creating roles and assigning provides to roles. Assign each role to group of users. This will simplify the job of assigning privileges to individual users.

77. What are Roles?

Ans. Roles are named groups of related privileges that are granted to users or other roles.

78. What are the use of Roles?

Ans. 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.

79. What is Privilege Auditing?

Ans. Privilege auditing is the auditing of the use of powerful system privileges without regard to specifically named objects.

80. What is Object Auditing?

Ans. Object auditing is the auditing of accesses to specific schema objects without regard to user.

81. What is Auditing?

Ans. Monitoring of user access to aid in the investigation of database use.

82. What are the responsibilities of a Database Administrator?

Ans.

1. Installing and upgrading the Oracle Server and application tools.

2. Allocating system storage and planning future storage requirements for the database system.

3. Managing primary database structures (tablespaces)

4. Managing primary objects (table, views, indexes)

5. Enrolling users and maintaining system security.

6. Ensuring compliance with Oracle license agreement

7. Controlling and monitoring user access to the database.

8. Monitoring and optimizing the performance of the database.

9. Planning for backup and recovery of database information.

10. Maintain archived data on tape

11. Backing up and restoring the database.

12. Contacting Oracle Corporation for technical support.

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

Ans. 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.

84. What is a profile?

Ans. Each database user is assigned a Profile that specifies limitations on various system resources available to the user.

85. How will you enforce security using stored procedures?

Ans. 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.

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

Ans. DBA_FREE_SPACE DBA_SEGMENTS DBA_DATA_FILES.

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

Ans. DBA - role contains all database system privileges. SYS user account - The DBA role will be assigned to this account. All of the base tables 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.

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

Ans. 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.

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

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

90. What is user Account in Oracle database?

Ans. 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.

91. What dynamic data replication?

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

92. What is Two-Phase Commit?

Ans. 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.

93. How can you Enforce Referential Integrity in snapshots?

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

94. 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.

95. 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.

96. What is the mechanism provided by ORACLE for table replication?

Snapshots and SNAPSHOT LOGs

97. What is snapshots?

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

98. What are the various type of snapshots?

Ans. Simple and Complex.

99. Describe two phases of Two-phase commit?

Ans. 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.

100. What is snapshot log?

Ans. 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.

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

Ans. 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.

102. What are the options available to refresh snapshots?

Ans. COMPLETE - Tables are completely regenerated using the snapshots 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.

103. What is a SNAPSHOT LOG?

Ans. 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.

104. What is Distributed database?

Ans. 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.

105. How can we reduce the network traffic?

Ans. Replication of data in distributed environment. - Using snapshots to replicate data. - Using remote procedure calls.

106. Differentiate simple and complex, snapshots?

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

107. What are the Built-ins used for sending Parameters to forms?

Ans. You can pass parameter values to a form when an application executes the call_form, New_form, Open_form or Run_product.

108. Can you have more than one content canvas view attached with a window?

Ans. Yes. Each window you create must have at least one content canvas view assigned to it. You can also create a window that has manipulated content canvas view. At run time only one of the content canvas views assign to a window is displayed at a time.

109. Is the After report trigger fired if the report execution fails?

Ans. Yes.

110. Does a Before form trigger fire when the parameter form is suppressed?

Ans. Yes.

111. Is it possible to split the print reviewer into more than one region?

Ans. Yes

112. Is it possible to center an object horizontally in a repeating frame that has a variable horizontal size?

Ans. Yes

113. For a field in a repeating frame, can the source come from the column which does not exist in the data group which forms the base for the frame?

Ans. Yes

114. Can a field be used in a report without it appearing in any data group?

Ans. Yes

115. The join defined by the default data link is an outer join yes or no?

Ans. Yes

116. Can a formula column referred to columns in higher group?

Ans. Yes

117. Can a formula column be obtained through a select statement?

Ans. Yes

118. Is it possible to insert comments into sql statements return in the data model editor? - Yes

119. Is it possible to disable the parameter from while running the report?

Ans. Yes

120. When a form is invoked with call_form, Does oracle forms issues a save point? –

Ans. Yes

121. Can a property clause itself be based on a property clause?

Ans. Yes

122. If a parameter is used in a query without being previously defined, what diff. exist between report 2.0 and 2.5 when the query is applied?

Ans. While both reports 2.0 and 2.5 create the parameter, report 2.5 gives a message that a bind parameter has been created.

123. What are the SQL clauses supported in the link property sheet?

Ans. Where start with having.

124. What is trigger associated with the timer?

Ans. When-timer-expired.

125. What are the trigger associated with image items?

Ans. When-image- activated fires when the operators double clicks on an image itemwhen-image- pressed fires when an operator clicks or double clicks on an image item

126. What are the different windows events activated at runtimes?

Ans. When_window_activated When_window_closed When_window_deactivated When_window_resized Within this triggers, you can examine the built in system variable system. event_window to determine the name of the window for which the trigger fired.

127. When do you use data parameter type? - When the value of a data parameter being passed to a called product is always the name of the record group defined in the current form. Data parameters are used to pass data to produts invoked with the run_product built-in subprogram.

128. What is difference between open_form and call_form?

Ans. when one form invokes another form by executing open_form the first form remains displayed, and operators can navigate between the forms as desired. when one form invokes another form by executing call_form, the called form is modal with respect to the calling form. That is, any windows that belong to the calling form are disabled, and operators cannot navigate to them until they first exit the called form.

129. What is new_form built-in?

Ans. When one form invokes another form by executing new_form oracle form exits the first form and releases its memory before loading the new form calling new form completely replace the first with the second. If there are changes pending in the first form, the operator will be prompted to save them before the new form is loaded.

130. What is the “LOV of Validation” Property of an item?

Ans. What is the use of it? - When LOV for Validation is set to True, Oracle Forms compares the current value of the text item to the values in the first column displayed in the LOV. Whenever the validation event occurs. If the value in the text item matches one of the values in the first column of the LOV, validation succeeds, the LOV is not displayed, and processing continues normally. If the value in the text item does not match one of the values in the first column of the LOV, Oracle Forms displays the LOV and uses the text item value as the search criteria to automatically reduce the list.

131. What is the diff. when Flex mode is mode on and when it is off?

Ans. When flex mode is on, reports automatically resizes the parent when the child is resized.

132. What is the diff. when confine mode is on and when it is off?

Ans. When confine mode is on, an object cannot be moved outside its parent in the layout.

133. What are visual attributes?

Ans. Visual attributes are the font, color, pattern proprieties that you set for form and menu objects that appear in your application interface.

134. Which of the two views should objects according to possession?

Ans. view by structure.

135. What are the two types of views available in the object navigator (specific to report 2.5)?

Ans. View by structure and view by type.

136. What are the vbx controls?

Ans. Vbx control provide a simple method of building and enhancing user interfaces. The controls can use to obtain user inputs and display program outputs.vbx control where originally develop as extensions for the ms visual basic environments and include such items as sliders, rides and knobs.

137. What is the use of transactional triggers?

Ans. Using transactional triggers we can control or modify the default functionality of the oracle forms.

138. How do you create a new session while open a new form?

Ans. Using open_form built-in setting the session option Ex. Open_form (’Stocks ‘,active,session). when invoke the mulitiple forms with open form and call_form in the same application, state whether the following are true/False

139. What are the ways to monitor the performance of the report?

Ans. Use reports profile executable statement. Use SQL trace facility.

140. If two groups are not linked in the data model editor, what is the hierarchy between them?

Ans. Two group that is above are the left most rank higher than the group that is to right or below it.

141. An open form cannot be execute the call_form procedure if you chain of called forms has been initiated by another open form?

Ans. True

142. Explain about horizontal, vertical tool bar canvas views?

Ans. Tool bar canvas views are used to create tool bars for individual windows. Horizontal tool bars are display at the top of a window, just under its menu bar. Vertical Tool bars are displayed along the left side of a window

143. What is the purpose of the product order option in the column property sheet?

Ans. To specify the order of individual group evaluation in a cross products.

144. What is the use of image_zoom built-in?

Ans. To manipulate images in image items.

145. How do you reference a parameter indirectly?

Ans. To indirectly reference a parameter use the NAME IN, COPY ‘built-ins to indirectly set and reference the parameters value’ Example name_in (’capital parameter my param’), Copy (’SURESH’,'Parameter my_param’)

Short Questions

1. What is a timer?

Ans. Timer is an “internal time clock” that you can programmatically create to perform an action each time the times.

2. What are the two phases of block coordination?

Ans. There are two phases of block coordination: the clear phase and the population phase. During, the clear phase, Oracle Forms navigates internally to the detail block and flushes the obsolete detail records. During the population phase, Oracle Forms issues a SELECT statement to repopulate the detail block with detail records associated with the new master record. These operations are accomplished through the execution of triggers.

3. What are Most Common types of Complex master-detail relationships?

Ans. There are three most common types of complex master-detail relationships: master with dependent details master with independent details detail with two masters

4. What is a text list?

Ans. The text list style list item appears as a rectangular box which displays the fixed number of values. When the text list contains values that cannot be displayed, a vertical scroll bar appears, allowing the operator to view and select values that are not displayed.

5. What is term?

Ans. The term is terminal definition file that describes the terminal form which you are using r20run.

6. What is use of term?

Ans. The term file which key is correspond to which oracle report functions.

7. What is pop list?

Ans. The pop list style list item appears initially as a single field (similar to a text item field). When the operator selects the list icon, a list of available choices appears.

8. What is the maximum no of chars the parameter can store?

Ans. The maximum no of chars the parameter can store is only valid for char parameters, which can be up to 64K. No parameters default to 23 Bytes and Date parameter default to 7 Bytes.

9. What are the default extensions of the files created by library module?

Ans. The default file extensions indicate the library module type and storage format .pll - pl/sql library module binary

10. What are the Coordination Properties in a Master-Detail relationship?

Ans. The coordination properties are Deferred Auto-Query These Properties determine when the population phase of block coordination should occur.

11. How do you display console on a window?

Ans. The console includes the status line and message line, and is displayed at the bottom of the window to which it is assigned. To specify that the console should be displayed, set the console window form property to the name of any window in the form. To include the console, set console window to Null.

12. What are the different Parameter types?

Ans. Text Parameters Data Parameters

13. State any three mouse events system variables?

Ans. System.mouse_button_pressedSystem.mouse_button_shift

14. What are the types of calculated columns available?

Ans. Summary, Formula, Placeholder column.

15. Explain about stacked canvas views?

Ans. Stacked canvas view is displayed in a window on top of, or “stacked” on the content canvas view assigned to that same window. Stacked canvas views obscure some part of the underlying content canvas view, and or often shown and hidden programmatically.

16. What are the built_ins used the display the LOV?

Ans. Show_lov List_values

17. What is the difference between SHOW_EDITOR and EDIT_TEXTITEM?

Ans. Show editor is the generic built-in which accepts any editor name and takes some input string and returns modified output string. Whereas the edit_textitem built-in needs the input focus to be in the text item before the built-in is executed.

18. What are the built-ins that are used to Attach an LOV programmatically to an item?

Ans. set_item_property get_item_property (by setting the LOV_NAME property)

19. How do you call other Oracle Products from Oracle Forms?

Ans. Run_product is a built-in, Used to invoke one of the supported oracle tools products and specifies the name of the document or module to be run. If the called product is unavailable at the time of the call, Oracle Forms returns a message to the operator.

20. What is the main diff. bet. Reports 2.0 & Reports 2.5?

Ans. Report 2.5 is object oriented.

21. What are the different file extensions that are created by oracle reports?

Ans. Rep file and Rdf file.

22. What is strip sources generate options?

Ans. Removes the source code from the library file and generates a library files that contains only pcode. The resulting file can be used for final deployment, but can not be subsequently edited in the designer.ex. f45gen module=old_lib.pll userid=scott/tiger strip_source YES output_file

23. What is the basic data structure that is required for creating an LOV?

Ans. Record Group.

24. What is the Maximum allowed length of Record group Column?

Ans. Record group column names cannot exceed 30 characters.

25. Which parameter can be used to set read level consistency across multiple queries?

Ans. Read only

26. What are the different types of Record Groups?

Ans. Query Record Groups NonQuery Record Groups State Record Groups

27. From which designation is it preferred to send the output to the printed?

Ans. Previewer

28. What are difference between post database commit and post-form commit?

Ans. Post-form commit fires once during the post and commit transactions process, after the database commit occurs. The post-form-commit trigger fires after inserts, updates and deletes have been posted to the database but before the transactions Have been finalized in the issuing the command. The post-database-commit trigger fires after oracle forms issues the commit to finalized transactions.

29. What are the different display styles of list items?

Ans. Pop_list Text_list Combo box

30. Which of the above methods is the faster method?

Ans. Performing the calculation in the query is faster.

31. With which function of summary item is the compute at options required?

Ans. Percentage of total functions.

32. What are parameters?

Ans. Parameters provide a simple mechanism for defining and setting the values of inputs that are required by a form at startup. Form parameters are variables of type char, number, date that you define at design time.

33. What are the three types of user exits available?

Ans. Oracle Precompiler exits, Oracle call interface, NonOracle user exits.

34. How many windows in a form can have console?

Ans. Only one window in a form can display the console, and you cannot change the console assignment at runtime

35. If the maximum record retrieved property of the query is set to 10 then a summary value will be calculated?

Ans. Only for 10 records.

36. What are the two repeating frame always associated with matrix object?

Ans. One down repeating frame below one across repeating frame.

37. What are the master-detail triggers?

Ans. On-Check_delete_master, On_clear_details, On_populate_details

38. What are the different objects that you cannot copy or reference in object groups?

Ans. Objects of different modules Another object groups Individual block dependent items Program units.

39. What is an OLE?

Ans. Object Linking & Embedding provides you with the capability to integrate objects from many Windows applications into a single compound document creating integrated applications enables you to use the features form.

40. Is it possible to modify an external query in a report which contains it?

Ans. No.

41. Does a grouping done for objects in the layout editor affect the grouping done in the data model editor?

Ans. No.

42. Can a repeating frame be created without a data group as a base?

Ans. No

43. If a break order is set on a column would it affect columns which are under the column?

Ans. No

44. Is it possible to set a filter condition in a cross product group in matrix reports?

Ans. No

45. Do user parameters appear in the data modal editor in 2.5?

Ans. No

46. Can you pass data parameters to forms?

Ans. No

47. Is it possible to link two groups inside a cross products after the cross products group has been created?

Ans. No

48. What are the different modals of windows?

Ans. Modeless windows Modal windows

49. What are modal windows?

Ans. Modal windows are usually used as dialogs, and have restricted functionality compared to modeless windows. On some platforms for example operators cannot resize, scroll or iconify a modal window.

50. What are the different default triggers created when Master Deletes Property is set to Non-isolated?

Ans. Master Deletes Property Resulting Triggers: Non-Isolated (the default) On-Check-Delete-Master On-Clear-Details On- Populate-Details

51. What are the different default triggers created when Master Deletes Property is set to isolated?

Ans. Master Deletes Property Resulting Triggers: Isolated On-Clear-Details On-Populate-Details

52. What are the different default triggers created when Master Deletes Property is set to Cascade?

Ans. Master Deletes Property Resulting Triggers: Cascading On-Clear-Details On-Populate-Details Pre-delete

53. What is the diff. bet. setting up of parameters in reports 2.0 reports2.5?

Ans. LOVs can be attached to parameters in the reports 2.5 parameter form.

54. What are the difference between lov & list item?

Ans. Lov is a property where as list item is an item. A list item can have only one column, lov can have one or more columns.

55. What is the advantage of the library?

Ans. Libraries provide a convenient means of storing client-side program units and sharing them among multiple applications. Once you create a library, you can attach it to any other form, menu, or library modules. When you can call library program units from triggers menu items commands and user named routine, you write in the modules to which you have attach the library. When a library attaches another library, program units in the first library can reference program units in the attached library. Library support dynamic loading-that is library program units are loaded into an application only when needed. This can significantly reduce the run-time memory requirements of applications.

56. What is lexical reference? - How can it be created?

Ans. Lexical reference is place_holder for text that can be embedded in a SQL statements. A lexical reference can be created using & before the column or parameter name.

57. What is system.coordination_operation?

Ans. It represents the coordination causing event that occur on the master block in master-detail relation.

58. What is synchronize?

Ans. It is a terminal screen with the internal state of the form. It updates the screen display to reflect the information that oracle forms has in its internal representation of the screen.

59. What use of command line parameter cmd file?

Ans. It is a command line argument that allows you to specify a file that contain a set of arguments for r20run.

60. What is a Text_io Package?

Ans. It allows you to read and write information to a file in the file system.

61. What is forms_DDL?

Ans. Issues dynamic Sql statements at run time, including server side pl/SQl and DDL

62. How is link tool operation different bet. reports 2 & 2.5?

Ans. In Reports 2.0 the link tool has to be selected and then two fields to be linked are selected and the link is automatically created. In 2.5 the first field is selected and the link tool is then used to link the first field to the second field.

63. What are the different styles of activation of ole Objects?

Ans. In place activation, External activation

64. How do you reference a Parameter?

Ans. In Pl/SQL, You can reference and set the values of form parameters using bind variables syntax. Ex. PARAMETER name = ‘’ or :block.item = PARAMETER Parameter name

65. What is the difference between object embedding & linking in Oracle forms?

Ans. In Oracle forms, Embedded objects become part of the form module, and linked objects are references from a form module to a linked source file.

66. Name of the functions used to get/set canvas properties?

Ans. Get_view_property, Set_view_property

67. What are the built-ins that are used for setting the LOV properties at runtime?

Ans. get_lov_property set_lov_property

68. What are the built-ins used for processing rows?

Ans.

Get_group_row_count(function) Get_group_selection_count(function) Get_group_selection(function) Reset_group_selection(procedure) Set_group_selection(procedure) Unset_group_selection(procedure)

69. What are built-ins used for Processing rows?

Ans.

GET_GROUP_ROW_COUNT(function) GET_GROUP_SELECTION_COUNT(function) GET_GROUP_SELECTION(function) RESET_GROUP_SELECTION(procedure) SET_GROUP_SELECTION(procedure) UNSET_GROUP_SELECTION(procedure)

70. What are the built-in used for getting cell values?

Ans. Get_group_char_cell(function) Get_groupcell(function) Get_group_number_cell(function)

71. What are the built-ins used for Getting cell values?

Ans.

GET_GROUP_CHAR_CELL (function) GET_GROUPCELL(function) GET_GROUP_NUMBET_CELL(function)

72. A tleast how many set of data must a data model have before a data model can be base on it?

Ans. Four

73. To execute row from being displayed that still use column in the row which property can be used?

Ans. Format trigger.

74. What are different types of modules available in oracle form?

Ans. Form module - a collection of objects and code routines Menu modules - a collection of menus and menu item commands that together make up an application menu library module - a collection of user named procedures, functions and packages that can be called from other modules in the application

75. What is the remove on exit property?

Ans. For a modeless window, it determines whether oracle forms hides the window automatically when the operators navigates to an item in the another window.

76. What is WHEN-Database-record trigger?

Ans. Fires when oracle forms first marks a record as an insert or an update. The trigger fires as soon as oracle forms determines through validation that the record should be processed by the next post or commit as an insert or update. Generally occurs only when the operators modifies the first item in the record, and after the operator attempts to navigate out of the item.

77. What is a difference between pre-select and pre-query?

Ans. Fires during the execute query and count query processing after oracle forms constructs the select statement to be issued, but before the statement is actually issued. The pre-query trigger fires just before oracle forms issues the select statement to the database after the operator as define the example records by entering the query criteria in enter query mode. Pre-query trigger fires before pre-select trigger.

78. What are built-ins associated with timers?

Ans. find_timer create_timer delete_timer

79. What are the built-ins used for finding object ID functions?

Ans. Find_group(function) Find_column(function)

80. What are the built-ins used for finding Object ID function?

Ans. FIND_GROUP(function) FIND_COLUMN(function)

81. Any attempt to navigate programmatically to disabled form in a call_form stack is allowed?

Ans. False

82. Use the Add_group_row procedure to add a row to a static record group 1. true or false?

Ans. False

83. Use the add_group_column function to add a column to record group that was created at a design time?

Ans. False

84. What are the various sub events a mouse double click event involves? What are the various sub events a mouse double click event involves?

Ans. Double clicking the mouse consists of the mouse down, mouse up, mouse click, mouse down & mouse up events.

85. How can a break order be created on a column in an existing group? What are the various sub events a mouse double click event involves?

Ans. By dragging the column outside the group.

86. What is the use of place holder column? What are the various sub events a mouse double click event involves?

Ans. A placeholder column is used to hold calculated values at a specified place rather than allowing is to appear in the actual row where it has to appear.

87. What is the use of hidden column? - What are the various sub events a mouse double click event involves?

Ans. A hidden column is used to when a column has to embed into boilerplate text.

88. What is the use of break group? - What are the various sub events a mouse double click event involves?

Ans. A break group is used to display one record for one group ones. While multiple related records in other group can be displayed.

89. What is an anchoring object & what is its use? - What are the various sub events a mouse double click event involves?

Ans. An anchoring object is a print condition object which used to explicitly or implicitly anchor other objects to itself.

90. What are the various sub events a mouse double click event involves?What are the various sub events a mouse double click event involves?

Ans. Double clicking the mouse consists of the mouse down, mouse up, mouse click, mouse down & mouse up events.

91. What are the default parameter that appear at run time in the parameter screen? What are the various sub events a mouse double click event involves?

Ans. Destype and Desname.

92. What are the built-ins used for Creating and deleting groups?

Ans.

CREATE- GROUP (function) CREATE_GROUP_FROM_QUERY(function) DELETE_GROUP(procedure)

93. What are different types of canvas views?

Ans. Content canvas views Stacked canvas views Horizontal toolbar vertical toolbar.

94. What are the different types of Delete details we can establish in Master- Details?

Ans. Cascade Isolate Non-isolate

95. What is relation between the window and canvas views?

Ans. Canvas views are the back ground objects on which you place the interface items (Text items), check boxes, radio groups etc.,) and boilerplate objects (boxes, lines, images etc.,) that operators interact with us they run your form . Each canvas views displayed in a window.

96. What is a User_exit?

Ans. Calls the user exit named in the user_exit_string. Invokes a 3Gl program by name which has been properly linked into your current oracle forms executable.

97. How is it possible to select generate a select set for the query in the query property sheet?

Ans. By using the tables/columns button and then specifying the table and the column names.

98. How can values be passed between precompiler exits & Oracle call interface?

Ans. By using the statement EXECIAFGET & EXECIAFPUT.

99. How can a square be drawn in the layout editor of the report writer?

Ans. By using the rectangle tool while pressing the (Constraint) key.

100. How can a text file be attached to a report while creating in the report writer?

Ans. By using the link file property in the layout boiler plate property sheet.

101. How can I message to passed to the user from reports?

Ans. By using SRW.MESSAGE function.

102. How is possible to restrict the user to a list of values while entering values for parameters?

Ans. By setting the Restrict To List property to true in the parameter property sheet.

103. How can a button be used in a report to give a drill down facility?

Ans. By setting the action associated with button to Execute pl/SQL option and using the SRW.Run_report function.

104. How can a cross product be created?

Ans. By selecting the cross products tool and drawing a new group surrounding the base group of the cross products.

105. What are different types of images?

Ans. Boiler plate images, Image Items

106. What is the difference between boiler plat images and image items?

Ans. Boiler plate Images are static images (Either vector or bit map) that you import from the file system or database to use a graphical elements in your form, such as company logos and maps. Image items are special types of interface controls that store and display either vector or bitmap images. Like other items that store values, image items can be either base table items (items that relate directly to database columns) or control items. The definition of an image item is stored as part of the form module FMB and FMX files, but no image file is actually associated with an image item until the item is populate at run time.

107. What is bind reference and how can it be created?

Ans. Bind reference are used to replace the single value in sql, pl/sql statements a bind reference can be created using a (:) before a column or a parameter name.

108. What are the triggers available in the reports?

Ans. Before report, Before form, After form , Between page, After report.

109. Give the sequence of execution of the various report triggers?

Ans. Before form , After form , Before report, Between page, After report.

110. Why is a Where clause faster than a group filter or a format trigger?

Ans. Because in a where clause the condition is applied during data retrieval, then after retrieving the data.

111. Why is it preferable to create a fewer no. of queries in the data model?

Ans. Because for each query, report has to open a separate cursor and has to rebind, execute and fetch data.

112. Where is the external query executed at the client or the server?

Ans. At the server.

113. Where is a procedure return in an external pl/SQL library executed at the client or at the server?

Ans. At the client.

114. What is coordination Event?

Ans. Any event that makes a different record in the master block the current record is a coordination causing event.

115. What is the difference between OLE Server & OLE Container?

Ans. An Ole server application creates ole Objects that are embedded or linked in ole Containers ex. Ole servers are ms_word & ms_excel. OLE containers provide a place to store, display and manipulate objects that are created by ole server applications. Ex. oracle forms is an example of an ole Container.

116. What is an object group?

Ans. An object group is a container for a group of objects; you define an object group when you want to package related objects, so that you copy or reference them in other modules.

117. What is an LOV?

Ans. An LOV is a scrollable popup window that provides the operator with either a single or multi column selection list.

118. At what point of report execution is the before Report trigger fired?

Ans. After the query is executed but before the report is executed and the records are displayed.

119. What are the built -ins used for Modifying a groups structure?

Ans.

ADD-GROUP_COLUMN (function) ADD_GROUP_ROW (procedure) DELETE_GROUP_ROW(procedure)

120. What is an user exit used for?

Ans. A way in which to pass control (and possibly arguments ) form Oracle report to another Oracle products of 3 GL and then return control ( and ) back to Oracle reports.

121. What is the User-Named Editor?

Ans. A user named editor has the same text editing functionality as the default editor, but, because it is a named object, you can specify editor attributes such as windows display size, position, and title.

122. What are the Built-ins to display the user-named editor?

Ans. A user named editor can be displayed programmatically with the built in procedure SHOW-EDITOR, EDIT_TETITEM independent of any particular text item.

123. What is a Static Record Group?

Ans. A static record group is not associated with a query, rather, you define its structure and row values at design time, and they remain fixed at runtime.

124. What is a record group?

Ans. A record group is an internal Oracle Forms that structure that has a column/row framework similar to a database table. However, unlike database tables, record groups are separate objects that belong to the form module which they are defined.

125. How many number of columns a record group can have?

Ans. A record group can have an unlimited number of columns of type CHAR, LONG, NUMBER, or DATE provided that the total number of column does not exceed 64K.

126. What is a Query Record Group?

Ans. A query record group is a record group that has an associated SELECT statement. The columns in a query record group derive their default names, data types, had lengths from the database columns referenced in the SELECT statement. The records in query record group are the rows retrieved by the query associated with that record group.

127. What is a Non Query Record Group?

128. What is a property clause?

Ans. A property clause is a named object that contains a list of properties and their settings. Once you create a property clause you can base other object on it. An object based on a property can inherit the setting of any property in the clause that makes sense for that object.

129. What is a physical page? What is a logical page?

A physical page is a size of a page. That is output by the printer. The logical page is the size of one page of the actual report as seen in the Previewer.

130. What does the term panel refer to with regarda to pages?

A panel is the number of physical pages needed to print one logical page.

131. What is a master detail relationship?

A master detail relationship is an association between two base table blocks- a master block and a detail block. The relationship between the blocks reflects a primary key to foreign key relationship between the tables on which the blocks are based.

132. What is a library?

A library is a collection of subprograms including user named procedures, functions and packages.

133. How can a group in a cross products be visually distinguished from a group that does not form a cross product?

A group that forms part of a cross product will have a thicker border.

134. What is the frame & repeating frame?

A frame is a holder for a group of fields. A repeating frame is used to display a set of records when the number of records that are to displayed is not known before.

135. What is a combo box?

Ans. A combo box style list item combines the features found in list and text item. Unlike the pop list or the text list style list items, the combo box style list item will both display fixed values and accept one operator entered value.

136. What are three panes that appear in the run time pl/SQL interpreter?

Ans. Source pane, interpreter pane, navigator pane.

137. What are the two panes that Appear in the design time pl/SQL interpreter?

Ans. Source pane, interpreter pane

138. What are the two ways by which data can be generated for a parameters list of values?

Ans. Using static values, writing select statement.

139. What are the various methods of performing a calculation in a report?

Ans. Perform the calculation in the SQL statements itself, use a calculated / summary column in the data model.

140. What are the default extensions of the files created by menu module?

Ans..mmb, .mmx

141. What are the default extensions of the files created by forms modules?

Ans..fmb - form module binary .fmx - form module executable

142. To display the page number for each page on a report, what would be the source & logical page number or physical page number?

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

Ans. Yes. The advantages over file system files. I/O will be improved because Oracle is bypassing the kernel when writing to disk. Disk Corruption will decrease.

144. What are disadvantages of having raw devices?

Ans. 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.

145. What is the significance of having storage clause?

Ans. 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.,

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

Ans. Type export should be performed COMPLETE, CUMULATIVE, INCREMENTAL. 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 a notion Completes. e. will be written.

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

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

148. What is a Shared SQL pool?

Ans. 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.

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

Ans. 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.

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

Ans.

1. SYSTEM - Data dictionary tables.

2. DATA - Standard operational tables.

3. DATA2- Static tables used for standard operations

4. INDEXES - Indexes for Standard operational tables.

5. INDEXES1 - Indexes of static tables used for standard operations.

6. TOOLS - Tools table.

7. TOOLS1 - Indexes for tools table.

8. RBS - Standard Operations Rollback Segments,

9. RBS1,RBS2 - Additional/Special Rollback segments.

10. TEMP - Temporary purpose tablespace

11. TEMP_USER - Temporary tablespace for users.

12. USERS - User tablespace.

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

Ans.

1. Shutdown the database

2. Copy one of the existing control file to new location

3. Edit Config ora file by adding new control filename

4. Restart the database.

152. 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 switches over to a working 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.

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

Ans. SET TRANSACTION USE ROLLBACK S

154. What is Index Cluster?

Ans. A Cluster with an index on the Cluster Key

155. When does a Transaction end?

Ans. When it is committed or Rollbacked.

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

Ans. 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).

Thank You.