Read the most frequently asked 150 top Database Administrator multiple choice questions and answers PDF for freshers and experienced. Database Administrator objective questions and answers pdf download free..
Database Administrator Multiple Choice Questions and Answers PDF Experienced Freshers
1. What is a DBA?
A DBA is a Database Administrator, and this is the most common job that you find a database specialist doing. There are Development DBAs and Production DBAs.
A Development DBA usually works closely with a team of developers and gets more involved in design decisions, giving advice on performance and writing good SQL.
That can be satisfying at a human level because you are part of a team and you share the satisfaction of the teams accomplishments.
A Production DBA (on the other hand) is responsible for maintaining Databases within an organization, so it is a very difficult and demanding job. He or she, often gets involved when all the design decisions have been made, and has simply to keep things up and running.
Therefore, of course, it is also a rewarding job, both financially and in terms of job satisfaction. But it is a more "lonely" job than being a Development DBA.
2. What DBA activities did you to do today?
This is a loaded question and almost begs for you to answer it with "What DBA activities do you LIKE to do on a daily basis?." And that is how I would answer this question. Again, do not get caught up in the "typical" day-to-day operational issues of database administration. Sure, you can talk about the index you rebuilt, the monitoring of system and session waits that were occurring, or the space you added to a data file, these are all good and great and you should convey that you understand the day-to-day operational issues. What you should also throw into this answer are the meetings that you attend to provide direction in the database arena, the people that you meet and talk with daily to answer adhoc questions about database use, the modeling of business needs within the database, and the extra time you spend early in the morning or late at night to get the job done. Just because the question stipulates "today" do not take "today" to mean "today." Make sure you wrap up a few good days into "today" and talk about them. This question also begs you to ask the question of "What typical DBA activities are performed day to day within X Corporation?"
3. 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.
4. 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.
5. Do you consider yourself a development DBA or a production DBA and why?
You take this as a trick question and explain it that way. Never in my database carrier have I distinguished between "development" and "production." Just ask your development staff or VP of engineering how much time and money is lost if development systems are down. Explain to the interviewer that both systems are equally important to the operation of the company and both should be considered as production systems because there are people relying on them and money is lost if either one of them is down. Ok you may be saying, and I know you are, that we lose more money if the production system is down. Ok, convey that to the interviewer and you won't get anyone to disagree with you unless your company sells software or there are million dollar deals on the table that are expecting the next release of your product or service.
6. What are the Large object types sported by Oracle?
1)bfile - Up to 4 gigabytes –> File locators that point to a read-only binary object outside of the database
2)blob - Up to 4 gigabytes. –> LOB locators that point to a large binary object within the database
3)clob - Up to 4 gigabytes. –> LOB locators that point to a large character object within the database
4)nclob - Up to 4 gigabytes. –>LOB locators that point to a large NLS character object within the database
7. Diffrence between a “where” clause and a “having” claus
Answer1
The order of the clauses in a query syntax using a GROUP BY clause is as follows:
select …where..group by…having…order by…
Where filters, group by arranges into groups, having applies based on group by clause. Having is applied with group by clause.
Answer2
In SQL Server, procedures and functions can return values. (In Oracle, procedures cannot directly return a value).
The major difference with a function is that it can be used in a value assignment. Such as:
–system function
Declare @mydate datetime
Set @mydate = getdate()
–user function (where the user has already coded the function)
Declare @My_area
Set @My_area = dbo.fn_getMy_area(15,20)
Answer3
1.”where” is used to filter records returned by “Select”
2.”where” appears before group by clause
3.In “where” we cannot use aggregate functions like where count(*) >2 etc
4.”having” appears after group by clause
5.”having” is used to filter records returned by “Group by”<
6.In”Having” we can use aggregate functions like where count(*) >2 etc there are two more
8. Shall we create procedures to fetch more than one record?
Yes. We can create procedures to fetch more than a row. By using CURSOR commands we could able to do that.
Ex:
CREATE OR REPLACE PROCEDURE myprocedure IS
CURSOR mycur IS select id from mytable;
new_id mytable.id%type;
BEGIN
OPEN mycur;
LOOP
FETCH mycur INTO new_id;
exit when mycur%NOTFOUND;
–do some manipulations–
END LOOP;
CLOSE mycur;
END myprocedure;
In this example iam trying to fetch id from the table mytable. So it fetches the id from each record until EOF.
(EXIT when mycur%NOTFOUND-is used to check EOF.
9. Do View contain Data?
Views do not contain or store data.
10. 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.
11. What are the type of Synonyms?
There are two types of Synonyms Private and Public
12. Where would you look for errors from the database engine?
In the alert log.
13. Compare and contrast TRUNCATE and DELETE for a table.
Both the truncate and delete command have the desired outcome of getting rid of all the rows in a table. The difference between the two is that the truncate command is a DDL operation and just moves the high water mark and produces a now rollback. The delete command, on the other hand, is a DML operation, which will produce a rollback and thus take longer to complete.
14. Give the reasoning behind using an index.
Faster access to data blocks in a table.
15. Give the two types of tables involved in producing a star schema and the type of data they hold.
Fact tables and dimension tables. A fact table contains measurements while dimension tables will contain data that will help describe the fact tables.
16. What type of index should you use on a fact table?
A Bitmap index.
17. What is a Segment?
A segment is a set of extents allocated for a certain logical structure.
18. A table is classified as a parent table and you want to drop and re-create it. How would you do this without affecting the children tables?
Disable the foreign key constraint to the parent, drop the table, re-create the table, enable the foreign key constraint.
19. Explain the difference between ARCHIVELOG mode and NOARCHIVELOG mode and the benefits and disadvantages to each.
ARCHIVELOG mode is a mode that you can put the database in for creating a backup of all transactions that have occurred in the database so that you can recover to any point in time. NOARCHIVELOG mode is basically the absence of ARCHIVELOG mode and has the disadvantage of not being able to recover to any point in time. NOARCHIVELOG mode does have the advantage of not having to write transactions to an archive log and thus increases the performance of the database slightly.
20. What is a Sequence?
A sequence generates a serial list of unique numbers for numerical columns of a database’s tables.
26. Explain the difference between $ORACLE_HOME and $ORACLE_BASE.
ORACLE_BASE is the root directory for oracle. ORACLE_HOME located beneath ORACLE_BASE is where the oracle products reside.
27. How would you determine the time zone under which a database was operating?
select DBTIMEZONE from dual;
28. Explain the use of setting GLOBAL_NAMES equal to TRUE.
Setting GLOBAL_NAMES dictates how you might connect to a database. This variable is either TRUE or FALSE and if it is set to TRUE it enforces database links to have the same name as the remote database to which they are linking.
29. What command would you use to encrypt a PL/SQL application?
WRAP
30. Explain the difference between a FUNCTION, PROCEDURE and PACKAGE.
A function and procedure are the same in that they are intended to be a collection of PL/SQL code that carries a single task. While a procedure does not have to return any values to the calling application, a function will return a single value. A package on the other hand is a collection of functions and procedures that are grouped together based on their commonality to a business function or application.
31. Explain the use of table functions.
Table functions are designed to return a set of rows through PL/SQL logic but are intended to be used as a normal table or view in a SQL statement. They are also used to pipeline information in an ETL process.
32. Name three advisory statistics you can collect.
Buffer Cache Advice
Segment Level Statistics
&
Timed Statistics
33. Where in the Oracle directory tree structure are audit traces placed?
In unix $ORACLE_HOME/rdbms/audit, in Windows the event viewer
34. Explain materialized views and how they are used.
Materialized views are objects that are reduced sets of information that have been summarized, grouped, or aggregated from base tables. They are typically used in data warehouse or decision support systems.
35. 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.
36. 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. 47.What is Index Cluster? - A Cluster with an
index on the Cluster Key 48.When does a Transaction end? - When it is committed or Rollbacked.
37. 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? - Answer The OPTIMIZER_MODE initialization parameter Statistics in the Data Dictionary the OPTIMIZER_GOAL parameter of the ALTER SESSION command hints in the statement.
38. Describe what redo logs are.
Redo logs are logical and physical structures that are designed to hold all the changes made to a database and are intended to aid in the recovery of a database.
39. How would you force a log switch?
ALTER SYSTEM SWITCH LOGFILE;
40. What are the different Parameter types?
Text ParametersData Parameters
41. What does coalescing a tablespace do?
Coalescing is only valid for dictionary-managed tablespaces and de-fragments space by combining neighboring free extents into large single extents.
42. What is the difference between a TEMPORARY tablespace and a PERMANENT tablespace?
A temporary tablespace is used for temporary objects such as sort structures while permanent tablespaces are used to store those objects meant to be used as the true objects of the database.
43. Name a tablespace automatically created when you create a database.
The SYSTEM tablespace.
44. When creating a user, what permissions must you grant to allow them to connect to the database?
Grant the CONNECT to the user.
45. How do you add a data file to a tablespace?
ALTER TABLESPACE ADD DATAFILE <datafile_name> SIZE <size>
46. How do you resize a data file?
ALTER DATABASE DATAFILE <datafile_name> RESIZE <new_size>;
47. What view would you use to look at the size of a data file?
DBA_DATA_FILES
48. What view would you use to determine free space in a tablespace?
DBA_FREE_SPACE
49. How would you determine who has added a row to a table?
Turn on fine grain auditing for the table.
50. How can you rebuild an index?
ALTER INDEX <index_name> REBUILD;.
51. Explain what partitioning is and what its benefit is.
Partitioning is a method of taking large tables and indexes and splitting them into smaller, more manageable pieces.
52. You have just compiled a PL/SQL package but got errors, how would you view the errors?
SHOW ERRORS
53. How can you gather statistics on a table?
The ANALYZE command.
54. How can you enable a trace for a session?
Use the DBMS_SESSION.SET_SQL_TRACE or
Use ALTER SESSION SET SQL_TRACE = TRUE;
55. What is the difference between the SQL*Loader and IMPORT utilities?
These two Oracle utilities are used for loading data into the database. The difference is that the import utility relies on the data being produced by another Oracle utility EXPORT while the SQL*Loader utility allows data to be loaded that has been produced by other utilities from different data sources just so long as it conforms to ASCII formatted or delimited files.
56. What is a database schema?
Answer1
The set of objects owned by user account is called the schema.
Answer2
Schema is the complete design of the database or data objects.
57. What are the options available to refresh snapshots?
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.
58. 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.
59. 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.
60. 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
61. What is database clusters?
Group of tables physically stored together because they share common columns and are often used together is called Cluster.
62. What is an Index? How it is implemented in Oracle Database?
An index is a database structure used by the server to have direct access of a row in a table. An index is automatically created when a unique of primary key constraint clause is specified in create table command (Ver 7.0)
63. 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.
64. What is the use of ANALYZE command?
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.
65. What is default tablespace?
The Tablespace to contain schema objects created without specifying a tablespace name.
66. 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 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.
67. What is Tablespace Quota?
The collective amount of disk space available to the objects in a schema on a particular tablespace.
68. What are the different Levels of Auditing?
Statement Auditing, Privilege Auditing and Object Auditing.
69. What is Statement Auditing?
Statement auditing is the auditing of the powerful system privileges without regard to specifically named objects
70. What are the database administrators utilities available?
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.
71. 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 database.
72. What are database roles?
Roles are named groups of related privileges that are granted to users or other roles.
73. How can we implement database roles?
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.
74. What are the use of database 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.
75. What is database Auditing?
To aid in the investigation of suspicious db use. Statement Auditing is the auditing of specific SQL statements. Privilege Auditing is the auditing of the use of powerful system privileges. Object Auditing is the auditing of access to specific schema objects.
76. What is Audit Trial?
Results of audited operations are stored in a table in data dictionary.
77. 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 Oracle license agreement
* Controlling and monitoring user access to the database.
* Monitoring and optimizing 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.
78. 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.
79. What is a database profile?
Each database user is assigned a Profile that specifies limitations on various system resources available to the user.
80. How will you enforce security using stored procedures?
Do not 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.
81. What are the dictionary tables used to monitor a database spaces?
DBA_FREE_SPACE DBA_SEGMENTS DBA_DATA_FILES.
82. 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 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.
83. 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.
84. 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 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.
85. 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. 95. 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).
86. What dynamic data replication?
Updating or Inserting records in remote database through database triggers. It may fail if remote database is having any problem.
87. 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.
88. How can you Enforce Referential Integrity in snapshots?
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.
89. What is a SQL * NET?
SQL *NET is ORACLEs 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.
90. 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.
91. What is the mechanism provided by ORACLE for table replication?
Snapshots and SNAPSHOT LOGs
92. What is database 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.
93. What are the various type of snapshots?
Simple and Complex.
94. 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.
95. 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.
96. 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.
97. What are clusters?
Group of tables physically stored together because they share common columns and are often used together is called cluster.
98. 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.
99. How can we reduce the network traffic?
Replication of data in distributed environment.
- Using snapshots to replicate data.
- Using remote procedure calls.
100. 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 snapshot of operations. - A complex snapshots contain at least any one of the above.
101. What are the Built-ins used for sending Parameters to forms?
You can pass parameter values to a form when an application executes the call_form, New_form, Open_form or Run_product.
102. Can you have more than one content canvas view attached with a window?
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.
103. Is the After report trigger fired if the report execution fails?
Yes. The After report trigger fired if the report execution fails.
104. Does a Before form trigger fire when the parameter form is suppressed?
Yes Before form trigger fire when the parameter form is suppressed
105. Is it possible to split the print reviewer into more than one region?
Yes it possible to split the print reviewer into more than one region
106. Is it possible to center an object horizontally in a repeating frame that has a variable horizontal size?
Yes it also possible to center an object horizontally in a repeating frame that has a variable horizontal size
107. How do you list the files in an UNIX directory while also showing hidden files?
ls -ltra
108. How do you execute a UNIX command in the background?
Use the "&"
Use the "*amp"
109. Can a formula column referred to columns in higher group?
Yes a formula column referred to columns in higher group
110. Can a formula column be obtained through a select statement?
Yes a formula column be obtained through a select statement
111. 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?
While both reports 2.0 and 2.5 create the parameter, report 2.5 gives a message that a bind parameter has been created.
112. What are the SQL clauses supported in the link property sheet?
Where start with having.
113. What is trigger associated with the timer?
When-timer-expired.
114. What are the trigger associated with image items?
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
115. What are the different windows events activated at runtimes?
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.
116. 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 products invoked with the run_product built-in subprogram.
117. What is difference between open_form and call_form?
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.
118. How would you change all occurrences of a value using VI?
Use :%s/<old>/<new>/g
119. Give two UNIX kernel parameters that effect an Oracle install
SHMMAX & SHMMNI
120. Briefly, how do you install Oracle software on UNIX.
Basically, set up disks, kernel parameters, and run orainst.
121. What is the diff. when confine mode is on and when it is off?
When confine mode is on, an object cannot be moved outside its parent in the layout.
122. What are visual attributes?
Visual attributes are the font, color, pattern proprieties that you set for form and menu objects that appear in your application interface.
123. Which of the two views should objects according to possession?
view by structure.
124. What are the two types of views available in the object navigator (specific to report 2.5)?
View by structure and view by type .
125. What are the vbx controls?
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.
126. What is the use of transactional triggers?
Using transactional triggers we can control or modify the default functionality of the oracle forms.
127. How do you create a new session while open a new form?
Using open_form built-in setting the session option Ex. Open_form (’Stocks ‘,active,session). when invoke the multiple forms with open form and call_form in the same application, state whether the following are true/False
128. What are the ways to monitor the performance of the report?
Use reports profile executable statement. Use SQL trace facility.
129. If two groups are not linked in the data model editor, What is the hierarchy between them?
Two group that is above are the left most rank higher than the group that is to right or below it.
130. An open form can not be execute the call_form procedure if you chain of called forms has been initiated by another open form?
True
131:: Explain about horizontal, Vertical tool bar canvas views?
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
132. What is the purpose of the product order option in the column property sheet?
To specify the order of individual group evaluation in a cross products.
133. What is the use of image_zoom built-in?
To manipulate images in image items.
134. How do you reference a parameter indirectly?
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’)
135. Is it possible to insert comments into sql statements return in the data model editor?
Yes it is possible to insert comments into sql statements return in the data model editor
136. Is it possible to disable the parameter from while running the report?
Yes it is possible to disable the parameter from while running the report
137. When a form is invoked with call_form, Does oracle forms issues a save point?
Yes oracle forms issues a save point when a form is invoked with call_form
138. Can a property clause itself be based on a property clause?
Yes a property clause itself be based on a property clause
139. What is a timer?
Timer is an “internal time clock” that you can programmatically create to perform an action each time the times.
140. What are the two phases of block coordination?
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.
141. What are Most Common types of Complex master-detail relationships?
There are three most common types of complex master-detail relationships: master with dependent details master with independent details detail with two masters
142. What is a text list?
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 can not be displayed, a vertical scroll bar appears, allowing the operator to view and select values that are not displayed.
143. What is term?
The term is terminal definition file that describes the terminal form which you are using r20run.
144. What is use of term?
The term file which key is correspond to which oracle report functions.
145. What is pop list?
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.
146. What is the maximum no of chars the parameter can store?
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.
147. What are the default extensions of the files created by library module?
The default file extensions indicate the library module type and storage format .pll - pl/sql library module binary
148. What are the Coordination Properties in a Master-Detail relationship?
The coordination properties are Deferred Auto-Query These Properties determine when the population phase of block coordination should occur.
149. What is an index and How it is implemented in Oracle database?
INDEX is a one which provides quick access to a row.
150. Lot of users are accessing select sysdate from dual and they getting some millisecond differences. If we execute SELECT SYSDATE FROM EMP; what error will we get. Why?
No error message indication will be there.
It displays the current system date.
Database Administrator Multiple Choice Questions and Answers PDF Experienced Freshers
A DBA is a Database Administrator, and this is the most common job that you find a database specialist doing. There are Development DBAs and Production DBAs.
A Development DBA usually works closely with a team of developers and gets more involved in design decisions, giving advice on performance and writing good SQL.
That can be satisfying at a human level because you are part of a team and you share the satisfaction of the teams accomplishments.
A Production DBA (on the other hand) is responsible for maintaining Databases within an organization, so it is a very difficult and demanding job. He or she, often gets involved when all the design decisions have been made, and has simply to keep things up and running.
Therefore, of course, it is also a rewarding job, both financially and in terms of job satisfaction. But it is a more "lonely" job than being a Development DBA.
2. What DBA activities did you to do today?
This is a loaded question and almost begs for you to answer it with "What DBA activities do you LIKE to do on a daily basis?." And that is how I would answer this question. Again, do not get caught up in the "typical" day-to-day operational issues of database administration. Sure, you can talk about the index you rebuilt, the monitoring of system and session waits that were occurring, or the space you added to a data file, these are all good and great and you should convey that you understand the day-to-day operational issues. What you should also throw into this answer are the meetings that you attend to provide direction in the database arena, the people that you meet and talk with daily to answer adhoc questions about database use, the modeling of business needs within the database, and the extra time you spend early in the morning or late at night to get the job done. Just because the question stipulates "today" do not take "today" to mean "today." Make sure you wrap up a few good days into "today" and talk about them. This question also begs you to ask the question of "What typical DBA activities are performed day to day within X Corporation?"
3. 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.
4. 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.
5. Do you consider yourself a development DBA or a production DBA and why?
You take this as a trick question and explain it that way. Never in my database carrier have I distinguished between "development" and "production." Just ask your development staff or VP of engineering how much time and money is lost if development systems are down. Explain to the interviewer that both systems are equally important to the operation of the company and both should be considered as production systems because there are people relying on them and money is lost if either one of them is down. Ok you may be saying, and I know you are, that we lose more money if the production system is down. Ok, convey that to the interviewer and you won't get anyone to disagree with you unless your company sells software or there are million dollar deals on the table that are expecting the next release of your product or service.
6. What are the Large object types sported by Oracle?
1)bfile - Up to 4 gigabytes –> File locators that point to a read-only binary object outside of the database
2)blob - Up to 4 gigabytes. –> LOB locators that point to a large binary object within the database
3)clob - Up to 4 gigabytes. –> LOB locators that point to a large character object within the database
4)nclob - Up to 4 gigabytes. –>LOB locators that point to a large NLS character object within the database
7. Diffrence between a “where” clause and a “having” claus
Answer1
The order of the clauses in a query syntax using a GROUP BY clause is as follows:
select …where..group by…having…order by…
Where filters, group by arranges into groups, having applies based on group by clause. Having is applied with group by clause.
Answer2
In SQL Server, procedures and functions can return values. (In Oracle, procedures cannot directly return a value).
The major difference with a function is that it can be used in a value assignment. Such as:
–system function
Declare @mydate datetime
Set @mydate = getdate()
–user function (where the user has already coded the function)
Declare @My_area
Set @My_area = dbo.fn_getMy_area(15,20)
Answer3
1.”where” is used to filter records returned by “Select”
2.”where” appears before group by clause
3.In “where” we cannot use aggregate functions like where count(*) >2 etc
4.”having” appears after group by clause
5.”having” is used to filter records returned by “Group by”<
6.In”Having” we can use aggregate functions like where count(*) >2 etc there are two more
8. Shall we create procedures to fetch more than one record?
Yes. We can create procedures to fetch more than a row. By using CURSOR commands we could able to do that.
Ex:
CREATE OR REPLACE PROCEDURE myprocedure IS
CURSOR mycur IS select id from mytable;
new_id mytable.id%type;
BEGIN
OPEN mycur;
LOOP
FETCH mycur INTO new_id;
exit when mycur%NOTFOUND;
–do some manipulations–
END LOOP;
CLOSE mycur;
END myprocedure;
In this example iam trying to fetch id from the table mytable. So it fetches the id from each record until EOF.
(EXIT when mycur%NOTFOUND-is used to check EOF.
9. Do View contain Data?
Views do not contain or store data.
10. 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.
11. What are the type of Synonyms?
There are two types of Synonyms Private and Public
12. Where would you look for errors from the database engine?
In the alert log.
13. Compare and contrast TRUNCATE and DELETE for a table.
Both the truncate and delete command have the desired outcome of getting rid of all the rows in a table. The difference between the two is that the truncate command is a DDL operation and just moves the high water mark and produces a now rollback. The delete command, on the other hand, is a DML operation, which will produce a rollback and thus take longer to complete.
14. Give the reasoning behind using an index.
Faster access to data blocks in a table.
15. Give the two types of tables involved in producing a star schema and the type of data they hold.
Fact tables and dimension tables. A fact table contains measurements while dimension tables will contain data that will help describe the fact tables.
16. What type of index should you use on a fact table?
A Bitmap index.
17. What is a Segment?
A segment is a set of extents allocated for a certain logical structure.
18. A table is classified as a parent table and you want to drop and re-create it. How would you do this without affecting the children tables?
Disable the foreign key constraint to the parent, drop the table, re-create the table, enable the foreign key constraint.
19. Explain the difference between ARCHIVELOG mode and NOARCHIVELOG mode and the benefits and disadvantages to each.
ARCHIVELOG mode is a mode that you can put the database in for creating a backup of all transactions that have occurred in the database so that you can recover to any point in time. NOARCHIVELOG mode is basically the absence of ARCHIVELOG mode and has the disadvantage of not being able to recover to any point in time. NOARCHIVELOG mode does have the advantage of not having to write transactions to an archive log and thus increases the performance of the database slightly.
20. What is a Sequence?
A sequence generates a serial list of unique numbers for numerical columns of a database’s tables.
26. Explain the difference between $ORACLE_HOME and $ORACLE_BASE.
ORACLE_BASE is the root directory for oracle. ORACLE_HOME located beneath ORACLE_BASE is where the oracle products reside.
27. How would you determine the time zone under which a database was operating?
select DBTIMEZONE from dual;
28. Explain the use of setting GLOBAL_NAMES equal to TRUE.
Setting GLOBAL_NAMES dictates how you might connect to a database. This variable is either TRUE or FALSE and if it is set to TRUE it enforces database links to have the same name as the remote database to which they are linking.
29. What command would you use to encrypt a PL/SQL application?
WRAP
30. Explain the difference between a FUNCTION, PROCEDURE and PACKAGE.
A function and procedure are the same in that they are intended to be a collection of PL/SQL code that carries a single task. While a procedure does not have to return any values to the calling application, a function will return a single value. A package on the other hand is a collection of functions and procedures that are grouped together based on their commonality to a business function or application.
31. Explain the use of table functions.
Table functions are designed to return a set of rows through PL/SQL logic but are intended to be used as a normal table or view in a SQL statement. They are also used to pipeline information in an ETL process.
32. Name three advisory statistics you can collect.
Buffer Cache Advice
Segment Level Statistics
&
Timed Statistics
33. Where in the Oracle directory tree structure are audit traces placed?
In unix $ORACLE_HOME/rdbms/audit, in Windows the event viewer
34. Explain materialized views and how they are used.
Materialized views are objects that are reduced sets of information that have been summarized, grouped, or aggregated from base tables. They are typically used in data warehouse or decision support systems.
35. 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.
36. 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. 47.What is Index Cluster? - A Cluster with an
index on the Cluster Key 48.When does a Transaction end? - When it is committed or Rollbacked.
37. 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? - Answer The OPTIMIZER_MODE initialization parameter Statistics in the Data Dictionary the OPTIMIZER_GOAL parameter of the ALTER SESSION command hints in the statement.
38. Describe what redo logs are.
Redo logs are logical and physical structures that are designed to hold all the changes made to a database and are intended to aid in the recovery of a database.
39. How would you force a log switch?
ALTER SYSTEM SWITCH LOGFILE;
40. What are the different Parameter types?
Text ParametersData Parameters
41. What does coalescing a tablespace do?
Coalescing is only valid for dictionary-managed tablespaces and de-fragments space by combining neighboring free extents into large single extents.
42. What is the difference between a TEMPORARY tablespace and a PERMANENT tablespace?
A temporary tablespace is used for temporary objects such as sort structures while permanent tablespaces are used to store those objects meant to be used as the true objects of the database.
43. Name a tablespace automatically created when you create a database.
The SYSTEM tablespace.
44. When creating a user, what permissions must you grant to allow them to connect to the database?
Grant the CONNECT to the user.
45. How do you add a data file to a tablespace?
ALTER TABLESPACE ADD DATAFILE <datafile_name> SIZE <size>
46. How do you resize a data file?
ALTER DATABASE DATAFILE <datafile_name> RESIZE <new_size>;
47. What view would you use to look at the size of a data file?
DBA_DATA_FILES
48. What view would you use to determine free space in a tablespace?
DBA_FREE_SPACE
49. How would you determine who has added a row to a table?
Turn on fine grain auditing for the table.
50. How can you rebuild an index?
ALTER INDEX <index_name> REBUILD;.
51. Explain what partitioning is and what its benefit is.
Partitioning is a method of taking large tables and indexes and splitting them into smaller, more manageable pieces.
52. You have just compiled a PL/SQL package but got errors, how would you view the errors?
SHOW ERRORS
53. How can you gather statistics on a table?
The ANALYZE command.
54. How can you enable a trace for a session?
Use the DBMS_SESSION.SET_SQL_TRACE or
Use ALTER SESSION SET SQL_TRACE = TRUE;
55. What is the difference between the SQL*Loader and IMPORT utilities?
These two Oracle utilities are used for loading data into the database. The difference is that the import utility relies on the data being produced by another Oracle utility EXPORT while the SQL*Loader utility allows data to be loaded that has been produced by other utilities from different data sources just so long as it conforms to ASCII formatted or delimited files.
56. What is a database schema?
Answer1
The set of objects owned by user account is called the schema.
Answer2
Schema is the complete design of the database or data objects.
57. What are the options available to refresh snapshots?
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.
58. 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.
59. 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.
60. 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
61. What is database clusters?
Group of tables physically stored together because they share common columns and are often used together is called Cluster.
62. What is an Index? How it is implemented in Oracle Database?
An index is a database structure used by the server to have direct access of a row in a table. An index is automatically created when a unique of primary key constraint clause is specified in create table command (Ver 7.0)
63. 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.
64. What is the use of ANALYZE command?
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.
65. What is default tablespace?
The Tablespace to contain schema objects created without specifying a tablespace name.
66. 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 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.
67. What is Tablespace Quota?
The collective amount of disk space available to the objects in a schema on a particular tablespace.
68. What are the different Levels of Auditing?
Statement Auditing, Privilege Auditing and Object Auditing.
69. What is Statement Auditing?
Statement auditing is the auditing of the powerful system privileges without regard to specifically named objects
70. What are the database administrators utilities available?
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.
71. 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 database.
72. What are database roles?
Roles are named groups of related privileges that are granted to users or other roles.
73. How can we implement database roles?
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.
74. What are the use of database 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.
75. What is database Auditing?
To aid in the investigation of suspicious db use. Statement Auditing is the auditing of specific SQL statements. Privilege Auditing is the auditing of the use of powerful system privileges. Object Auditing is the auditing of access to specific schema objects.
76. What is Audit Trial?
Results of audited operations are stored in a table in data dictionary.
77. 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 Oracle license agreement
* Controlling and monitoring user access to the database.
* Monitoring and optimizing 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.
78. 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.
79. What is a database profile?
Each database user is assigned a Profile that specifies limitations on various system resources available to the user.
80. How will you enforce security using stored procedures?
Do not 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.
81. What are the dictionary tables used to monitor a database spaces?
DBA_FREE_SPACE DBA_SEGMENTS DBA_DATA_FILES.
82. 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 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.
83. 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.
84. 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 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.
85. 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. 95. 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).
86. What dynamic data replication?
Updating or Inserting records in remote database through database triggers. It may fail if remote database is having any problem.
87. 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.
88. How can you Enforce Referential Integrity in snapshots?
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.
89. What is a SQL * NET?
SQL *NET is ORACLEs 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.
90. 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.
91. What is the mechanism provided by ORACLE for table replication?
Snapshots and SNAPSHOT LOGs
92. What is database 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.
93. What are the various type of snapshots?
Simple and Complex.
94. 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.
95. 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.
96. 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.
97. What are clusters?
Group of tables physically stored together because they share common columns and are often used together is called cluster.
98. 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.
99. How can we reduce the network traffic?
Replication of data in distributed environment.
- Using snapshots to replicate data.
- Using remote procedure calls.
100. 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 snapshot of operations. - A complex snapshots contain at least any one of the above.
101. What are the Built-ins used for sending Parameters to forms?
You can pass parameter values to a form when an application executes the call_form, New_form, Open_form or Run_product.
102. Can you have more than one content canvas view attached with a window?
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.
103. Is the After report trigger fired if the report execution fails?
Yes. The After report trigger fired if the report execution fails.
104. Does a Before form trigger fire when the parameter form is suppressed?
Yes Before form trigger fire when the parameter form is suppressed
105. Is it possible to split the print reviewer into more than one region?
Yes it possible to split the print reviewer into more than one region
106. Is it possible to center an object horizontally in a repeating frame that has a variable horizontal size?
Yes it also possible to center an object horizontally in a repeating frame that has a variable horizontal size
107. How do you list the files in an UNIX directory while also showing hidden files?
ls -ltra
108. How do you execute a UNIX command in the background?
Use the "&"
Use the "*amp"
109. Can a formula column referred to columns in higher group?
Yes a formula column referred to columns in higher group
110. Can a formula column be obtained through a select statement?
Yes a formula column be obtained through a select statement
111. 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?
While both reports 2.0 and 2.5 create the parameter, report 2.5 gives a message that a bind parameter has been created.
112. What are the SQL clauses supported in the link property sheet?
Where start with having.
113. What is trigger associated with the timer?
When-timer-expired.
114. What are the trigger associated with image items?
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
115. What are the different windows events activated at runtimes?
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.
116. 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 products invoked with the run_product built-in subprogram.
117. What is difference between open_form and call_form?
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.
118. How would you change all occurrences of a value using VI?
Use :%s/<old>/<new>/g
119. Give two UNIX kernel parameters that effect an Oracle install
SHMMAX & SHMMNI
120. Briefly, how do you install Oracle software on UNIX.
Basically, set up disks, kernel parameters, and run orainst.
121. What is the diff. when confine mode is on and when it is off?
When confine mode is on, an object cannot be moved outside its parent in the layout.
122. What are visual attributes?
Visual attributes are the font, color, pattern proprieties that you set for form and menu objects that appear in your application interface.
123. Which of the two views should objects according to possession?
view by structure.
124. What are the two types of views available in the object navigator (specific to report 2.5)?
View by structure and view by type .
125. What are the vbx controls?
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.
126. What is the use of transactional triggers?
Using transactional triggers we can control or modify the default functionality of the oracle forms.
127. How do you create a new session while open a new form?
Using open_form built-in setting the session option Ex. Open_form (’Stocks ‘,active,session). when invoke the multiple forms with open form and call_form in the same application, state whether the following are true/False
128. What are the ways to monitor the performance of the report?
Use reports profile executable statement. Use SQL trace facility.
129. If two groups are not linked in the data model editor, What is the hierarchy between them?
Two group that is above are the left most rank higher than the group that is to right or below it.
130. An open form can not be execute the call_form procedure if you chain of called forms has been initiated by another open form?
True
131:: Explain about horizontal, Vertical tool bar canvas views?
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
132. What is the purpose of the product order option in the column property sheet?
To specify the order of individual group evaluation in a cross products.
133. What is the use of image_zoom built-in?
To manipulate images in image items.
134. How do you reference a parameter indirectly?
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’)
135. Is it possible to insert comments into sql statements return in the data model editor?
Yes it is possible to insert comments into sql statements return in the data model editor
136. Is it possible to disable the parameter from while running the report?
Yes it is possible to disable the parameter from while running the report
137. When a form is invoked with call_form, Does oracle forms issues a save point?
Yes oracle forms issues a save point when a form is invoked with call_form
138. Can a property clause itself be based on a property clause?
Yes a property clause itself be based on a property clause
139. What is a timer?
Timer is an “internal time clock” that you can programmatically create to perform an action each time the times.
140. What are the two phases of block coordination?
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.
141. What are Most Common types of Complex master-detail relationships?
There are three most common types of complex master-detail relationships: master with dependent details master with independent details detail with two masters
142. What is a text list?
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 can not be displayed, a vertical scroll bar appears, allowing the operator to view and select values that are not displayed.
143. What is term?
The term is terminal definition file that describes the terminal form which you are using r20run.
144. What is use of term?
The term file which key is correspond to which oracle report functions.
145. What is pop list?
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.
146. What is the maximum no of chars the parameter can store?
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.
147. What are the default extensions of the files created by library module?
The default file extensions indicate the library module type and storage format .pll - pl/sql library module binary
148. What are the Coordination Properties in a Master-Detail relationship?
The coordination properties are Deferred Auto-Query These Properties determine when the population phase of block coordination should occur.
149. What is an index and How it is implemented in Oracle database?
INDEX is a one which provides quick access to a row.
150. Lot of users are accessing select sysdate from dual and they getting some millisecond differences. If we execute SELECT SYSDATE FROM EMP; what error will we get. Why?
No error message indication will be there.
It displays the current system date.
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