101. What is the mechanism provided by ORACLE for table replication ?
Snapshots and SNAPSHOT LOGs
102. What is snapshots?
Snapshot is an object used to dynamically replicate data between distribute database at specified time intervals. In ver 7.0 they are read only.
103. What are the various type of snapshots?
Simple and Complex.
104. 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.
105. 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.
106. 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.
107. 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.
108. 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.
109. 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.
110. How can we reduce the network traffic?
- Replication of data in distributed enviroonment.
- Using snapshots to replicate data.
- Using remote procedure calls.
111. Differentiate simple and complex, snapshots ?
- A simple snapshot is based on a query thaat does not contains GROUP BY clauses, CONNECT BY clauses, JOINs, sub-query or snashot of operations.
- A complex snapshots contain atleast any oone of the above.
112. 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.
113. Can you have more than one content canvas view attached with a window?
Yes. Each window you create must have atleast 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.
114. Is the After report trigger fired if the report execution fails?
Yes.
115. Does a Before form trigger fire when the parameter form is suppressed?
Yes.
116. Is it possible to split the print reviewer into more than one region?
Yes
117. Is it possible to center an object horizontally in a repeating frame that has a variable horizontal size?
Yes
118. 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?
Yes
119. Can a field be used in a report without it appearing in any data group?
Yes
120. The join defined by the default data link is an outer join yes or no?
Yes
121. Can a formula column referred to columns in higher group?
Yes
122. Can a formula column be obtained through a select statement?
Yes
123. Is it possible to insert comments into sql statements return in the data model editor?
Yes
124. Is it possible to disable the parameter from while running the report?
Yes
126. When a form is invoked with call_form, Does oracle forms issues a save point?
Yes
127. Can a property clause itself be based on a property clause?
Yes
128. If a parameter is used in a query without being previously defined, what diff. exist betw. 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.
129. What are the sql clauses supported in the link property sheet?
Where start with having.
130. What is trigger associated with the timer?
When-timer-expired.
131. 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
132. 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.
133. 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.
134. 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.
135. What is new_form built-in?
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.
136. What is the "LOV of Validation" Property of an item? 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.
137. What is the diff. when Flex mode is mode on and when it is off?
When flex mode is on, reports automatically resizes the parent when the child is resized.
138. 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.
139. 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.
140. Which of the two views should objects according to possession?
view by structure.
141. What are the two types of views available in the object navigator(specific to report 2.5)?
View by structure and view by type .
142. What are the vbx controls?
Vbx control provide a simple method of building and enhancing user interfaces.
143. What is the use of transactional triggers?
Using transactional triggers we can control or modify the default functionality of the oracle forms.
144. 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 mulitiple forms with open form and call_form in the same application, state whether the
following are true/False
145. What are the ways to monitor the performance of the report?
Use reports profile executable statement. Use SQL trace facility.
146. 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.
147. 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
148. 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
149. 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.
150. What is the use of image_zoom built-in?
To manipulate images in image items.
