ORACLE DBA INTERVIEW QUESTIONS ANSWERS PDF
Oracle DBA interview questions - Free download as Word Doc .doc), PDF File . pdf), Text File .txt) or read Oracle Interview Questions and Answers: SQL. 1. If you're looking for Oracle DBA Interview Questions for Experienced or Freshers, you are at right place. There are a lot of opportunities from many reputed. Top 40 oracle dba interview questions and answers. 3 Comments .. Download of oracle dba interview questions as PDF is also given below.
|Language:||English, Spanish, French|
|Genre:||Business & Career|
|ePub File Size:||22.52 MB|
|PDF File Size:||12.75 MB|
|Distribution:||Free* [*Regsitration Required]|
Oracle DBA Interview Questions Answers. By. Gitesh Trivedi. Publisher: Kendba Services. Copy right protected @ Kendba Services. Oracle DBA Interview Questions 1. Explain the difference between a hot backup and a cold backup and the benefits associated with each. A hot backup is. Answer: The On-line Redo Log is a set of tow or more on-line redo files that record all committed changes made to the database. Whenever a transaction is.
What Is Data Block? Answer : Oracle database's data is stored in data blocks. One data block corresponds to a specific number of bytes of physical database space on disk. Answer : 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 data blocks. Block size is specified in init. What Is Row Chaining? Answer : In circumstances, all of the data for a row in a table may not be able to fit in the same data block.
When this occurs, the data for the row is stored in a chain of data block one or more reserved for that segment. What Is An Extent? Question 1. RMAN is faster, can do incremental changes only backups, and does not place tablespaces into hotbackup mode.
Question 2. This avoids a hard parse each time, which saves on various locking and latching resources we use to check objects existence and so on. Question 3. This is slow, and uses up resources. If we loop on an SQL statement, we are implicitely flipping between these two engines.
Question 4. Question 5. Question 6. Which Is Better For Oracle? RAID 5 is striping with an extra disk for parity. If we lose a disk we can reconstruct from that parity disk. RAID 5 was created when disks were expensive. Its purpose was to provide RAID on the cheap. What's more your liklihood of failure increases dramatically during this period, with all the added weight of the rebuild.
Even when it is operating normally RAID 5 is slow for everything but reading. Don't put redologs on RAID5.
Oracle DBA Interview Questions
RAID10 is just all around goodness. If you lose one disk in a set of 10 for example, you could lose any one of eight other disks and have no troubles. What's more rebuilding does not impact performance at all since you're simply making a mirror copy. Lastly RAID10 perform exceedingly well in all types of databases.
Question 7. How Do You Handle Them? Also be wary of multi-byte characters sets as those may require extra attention. Question 8. Question 9. Explain Two Easy Sql Optimizations? Question Why Is One Faster?
Can We Rollback Both? Truncate is nearly instantaenous, cannot be rolled back, and is fast because Oracle simply resets the HWM. When a full table scan is performed on a table, such as for a sort operation, Oracle reads to the HWM. So if you delete every single solitary row in 10 million row table so it is now empty, sorting on that table of 0 rows would still be extremely slow.
Fast refresh maintains a change log table, which records change vectors, not unlike how the redo logs work. There is overhead to this, as with a table that has a LOT of indexes on it, and inserts and updates will be slower. However if you are performing refreshes often, like every few minutes, you want to do fast refresh so you don't have to full-table-scan the source table. Complete refresh is good if you're going to refresh once a day.
Why Would We Use It? It disables the logging of changes to the redologs. However it will cause problems if you are using standby database.
Use it to speed up operations, like an index rebuild, or partition maintenance operations. 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. They are also used to pipeline information in an ETL process.
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. 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. Coalescing is only valid for dictionary-managed tablespaces and de-fragments space by combining neighboring free extents into large single extents.
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.
Partitioning is a method of taking large tables and indexes and splitting them into smaller, more manageable pieces. These two Oracle utilities are used for loading data into the database. Read allows you to see and list the directory contents. A symbolic soft linked file and the targeted file can be located on the same or different file system while for a hard link they must be located on the same file system.
Explain Iostat, Vmstat And Netstat? Basically, set up disks, kernel parameters, and run orainst. Oracle Database must have at least one control file. It's a binary file contains some of the following information:. Oracle first opens and reads the initialization parameter file init. System Monitor Process - Performs recovery after instance failure, monitors temporary segments and extents; cleans temp segments, coalesces free space mandatory process for DB and starts by default.
Process Monitor - Recovers failed process resources. In Shared Server architecture, monitors and retarts any failed dispatcher or server proceses mandatory process for DB and starts by default. What Is Instance Recovery? While Oracle instance fails, Oracle performs an Instance Recovery when the associated database is being re-started. Cache recovery: Changes being made to a database are recorded in the database buffer cache. These changes are also recorded in online redo log files simultaneously.
When there are enough data in the database buffer cache,they are written to data files. If an Oracle instance fails before the data in the database buffer cache are written to data files, Oracle uses the data recorded in the online redo log files to recover the lost data when the associated database is re-started.
This process is called cache recovery. Transaction recovery: When a transaction modifies data in a database, the before image of the modified data is stored in an undo segment. The data stored in the undo segment is used to restore the original values in case a transaction is rolled back.
At the time of an instance failure, the database may have uncommitted transactions. It is possible that changes made by these uncommitted transactions have gotten saved in data files. To maintain read consistency, Oracle rolls back all uncommitted transactions when the associated database is re-started. Oracle uses the undo data stored in undo segments to accomplish this. This process is called transaction recovery. The maxdatafiles parameter is a different - "hard limit" parameter.
When issuing a "create database" command, the value specified for maxdatafiles is stored in Oracle control files and default value is Regardless of the setting of this paramter, maximum per database: What Is A Tablespace? A tablespace is a logical storage unit within an Oracle database. Tablespace is not visible in the file system of the machine on which the database resides. A tablespace, in turn, consists of at least one datafile which, in turn, are physically located in the file system of the server.
A datafile belongs to exactly one tablespace. Each table, index and so on that is stored in an Oracle database belongs to a tablespace. The tablespace builds the bridge between the Oracle database and the filesystem in which the table's or index' data is stored. Before Oracle changes data in a datafile it writes these changes to the redo log. If something happens to one of the datafiles, a backed up datafile can be restored and the redo, that was written since, replied, which brings the datafile to the state it had before it became unavailable.
The following query lists all the roles in the database:. What Is A Checkpoint? A checkpoint occurs when the DBWR database writer process writes all modified buffers in the SGA buffer cache to the database data files.
Data file headers are also updated with the latest checkpoint SCN, even if the file had no changed blocks. Checkpoints occur AFTER not during every redo log switch and also at intervals specified by initialization parameters.
Oracle creates server processes to handle requests from connected user processes. A server process communicates with the user process and interacts with Oracle to carry out requests from the associated user process. For example, if a user queries some data not already in the database buffers of the SGA, then the associated server process reads the proper data blocks from the datafiles into the SGA.
Oracle can be configured to vary the number of user processes for each server process. In a dedicated server configuration, a server process handles requests for a single user process. A shared server configuration lets many user processes share a small number of server processes, minimizing the number of server processes and maximizing the use of available system resources. Database Writer background process DBWn 20 possible writes dirty buffers from the buffer cache to the data files.
In other words, this process writes modified blocks permanently to disk. If Yes, How? A Datafile can be auto extendible. Here's how to enable auto extend on a Datafile: DBF' autoextend on. What Is A Shared Pool? The shared pool portion of the SGA contains the library cache, the dictionary cache, buffers for parallel execution messages, and control structures.
Oracle DBA Interview Questions
The default value of this parameter is 8MB on bit platforms and 64MB on bit platforms. Increasing the value of this parameter increases the amount of memory reserved for the shared pool. The database buffer cache is the portion of the SGA that holds copies of data blocks read from datafiles. All user processes concurrently connected to the instance share access to the database buffer cache.
The large pool is an optional memory area and provides large memory allocations for:. This eliminates holes created by row deletions and maximizes contiguous free space in blocks.
Oracle will only insert new rows in blocks that is enqueued on the freelist. Row Migration: Row Migration refers to rows that were moved to another blocks due to an update making them too large to fit into their original blocks. Oracle will leave a forwarding pointer in the original block so indexes will still be able to "find" the row. Note that Oracle does not discriminate between chained and migrated rows, even though they have different causes.
A chained row is a row that is too large to fit into a single database data block. For example, if you use a 4KB blocksize for your database, and you need to insert a row of 8KB into it, Oracle will use 3 blocks and store the row in pieces.
Detecting row chaining: This query will show how many chained and migrated rows each table has: Locally Managed Tablespace is a tablespace that record extent allocation in the tablespace header. Each tablespace manages it's own free and used space within a bitmap structure stored in one of the tablespace's data files. Can You Audit Select Statements? Plus, all data in the audit trail must also be audited to see who has selected data from the audit trail.
What Is Cost Based Optimization? The cost is based on the number of rows in a table, index efficiency, etc.
All applications should be converted to use the Cost Based Optimizer as the Rule Based Optimizer is not be supported in Oracle 10g and above releases. This job can be disabled with this command: In general, you should create an index on a column in any of the following situations:.
They are similar construct to a binary tree, they provide fast access by key, to an individual row or range of rows, normally requiring very few reads to find the correct row.
Bitmap Indexes - With a bitmap index , a single index entry uses a bitmap to point to many rows simultaneously, they are used with low data that is mostly read-only.
Schould be avoided in OLTP systems. Application Domain Indexes - These are indexes you build and store yuorself, either in Oracle or outside of Oracle interMedia Text Indexes - This is a specialised index built into Oracle to allow for keyword searching of large bodies of text. What Is B-tree Index? A B-Tree index is a data structure in the form of a tree, but it is a tree of database blocks, not rows. Small tables do not require indexes; if a query is taking too long, then the table might have grown from small to large.
You can create an index on any column; however, if the column is not used in any of these situations, creating an index on the column does not increase performance and the index takes up resources unnecessarily. Each column contains less than distinct values by themselves, and a b-tree index would be fairly useless in a database of 20 million vehicles.
When Should You Rebuilt Indexes? When the data in index is sparse lots of holes in index, due to deletes or updates and your query is usually range based.
Also index blevel is one of the key indicators of performance of sql queries doing Index range scans. Can You Built Indexes Online? You can create and rebuild indexes online.
This enables you to update base tables at the same time you are building or rebuilding indexes on that table. Parallel execution is not supported when creating or rebuilding an index online. The following statements illustrate online index build operations: What Is Statspack Tool? That's possible. It's a lot quicker to bounce the instance when changing this. This is achievable with Oracle Resource Manager. It also provides semantics so that you may group together changes to the plan schema.
The operation cannot be rolled back and no triggers will be fired. A direct path load eliminates much of the Oracle database overhead by formatting Oracle data blocks and writing the data blocks directly to the database files. Global Index: Range Partitioning maps data to partitions based on a range of column values e. Oracle Database creates server processes to handle the requests of user processes connected to an instance. Your database is always enabled to allow dedicated server processes, but you must specifically configure and enable shared server by setting one or more initialization parameters.
Different versions of the import utility are upwards compatible.
This means that one can take an export file created from an old export version, and import it using a later version of the import utility. Oracle also ships some previous catexpX. Oracle database is comprised of three types of files. One or more datafiles, two are more redo log files, and one or more control files.
There are tablespaces and database's schema objects. A database is divided into Logical Storage Unit called tablespaces. A tablespace is used to grouped related logical structures together. Each databases logically divided into one or more tablespaces one or more data files are explicitly created for each tablespace.
What Is Schema? A schema is collection of database objects of a user. What Are Schema Objects? Schema objects are the logical structures that directly refer to the database's data. Schema objects include tables, views, sequences, synonyms, indexes, clusters, database triggers, procedures, functions packages and database links. What Is Oracle Table? A table is the basic unit of data storage in an Oracle database.
The tables of a database hold all of the user accessible data. Table data is stored in rows and columns. What Is An Oracle View? Every view has a query attached to it.
What Is Partial Backup? A Partial Backup is any operating system backup short of a full backup, taken while the database is open or shut down. 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.
What Is Full Backup? A full backup is an operating system backup of all data files, on-line redo log files and control file that constitute ORACLE database and the parameter. 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. Do View Contain Data? There are two types of Synonyms Private and Public. What Is A Redo Log? What Is An Index Segment? Each Index has an Index segment that stores all of its data. What Are Clusters? Clusters are groups of one or more tables physically stores together to share common columns and are often used together.
What Is An Integrity Constrains? An integrity constraint is a declarative way to define a business rule for a column of a table. What Is An Index?
An Index is an optional structure associated with a table to have direct access to rows, which can be created to increase the performance of data retrieval. Index can be created on one or more columns of a table. What Is An Extent? An Extent is a specific number of contiguous data blocks, obtained in a single allocation, and used to store a specific type of information.
What Is A View? A view is a virtual table. Every view has a Query attached to it. What Is Table? Provide an additional level of table security, by restricting access to a predetermined set of rows and columns of a table. Hide data complexity. Simplify commands for the user.
Present the data in a different perspective from that of the base table. Store complex queries. What Is An Oracle Sequence?
A sequence generates a serial list of unique numbers for numerical columns of a database's tables. What Is A Synonym?
A synonym is an alias for a table, view, sequence or program unit. There are two types of synonyms private and public. What Is A Private Synonym? Only its owner can access a private synonym. What Is A Public Synonym?
Any database user can access a public synonym. What Are Synonyms Used For? Mask the real name and owner of an object. Provide public access to an object. Provide location transparency for tables, views or program units of a remote database. Simplify the SQL statements for database users. What Is An Oracle Index? An index is an optional structure associated with a table to have direct access to rows, which can be created to increase the performance of data retrieval.
How Are The Index Updates? Indexes are automatically maintained and used by Oracle. Changes to table data are automatically incorporated into all relevant indexes.
What Is Rollback Segment? A Database contains one or more Rollback Segments to temporarily store "undo" information. 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. Block size is specified in INIT. ORA file and can't be changed latter. What Is Index Cluster? When Does A Transaction End?
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. What Does Commit Do? The changes made by the SQL statements of a transaction become visible to other user sessions transactions that start only after transaction is committed.
What Is Read-only Transaction? A Read-Only transaction ensures that the results of each query executed in the transaction are consistant with respect to the same point in time. What Is A Deadlock? Two processes wating to update the rows of a table which are locked by the other process then deadlock arises.
In a database environment this will often happen because of not issuing proper row lock commands. Poor design of front-end application may cause this situation and the performance of server will reduce drastically. What Is A Schema? The set of objects owned by user account is called the schema. 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.
What Is Parallel Server? What Is Clusters? Group of tables physically stored together because they share common columns and are often used together is called Cluster.
An index is a database structure used by the server to have direct access of a row in a table. An index is automatically created when a unique of primary key constraint clause is specified in create table comman Ver 7.
What Is A Database Instance? 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. To perform one of these function on an index,table, or cluster:. What Is Default Tablespace? The Tablespace to contain schema objects created without specifying a tablespace name.
What Is Tablespace Quota?
The collective amount of disk space available to the objects in a schema on a particular tablespace. What Is Statement Auditing? Statement auditing is the auditing of the powerful system privileges without regard to specifically named objects. Shut the database. Backup the database. Start up the database. What Are Roles? How Can We Implement Roles? Roles are the easiest way to grant and manage common privileges needed by different groups of database users.
Creating roles and assigning provides to roles. Assign each role to group of users. This will simplify the job of assigning privileges to individual users. Roles are named groups of related privileges that are granted to users or other roles. What Is Privilege Auditing? Privilege auditing is the auditing of the use of powerful system privileges without regard to specifically named objects.
What Is Object Auditing? Object auditing is the auditing of accesses to specific schema objects without regard to user.
What Is A Profile? Each database user is assigned a Profile that specifies limitations on various system resources available to the user. 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. 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. We must be able to create a after row trigger on table i. 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. What Dynamic Data Replication? Updating or Inserting records in remote database through database triggers. It may fail if remote database is having any problem. 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. Time the references to occur when master tables are not in use. Peform the reference the manually immdiately locking the master tables.
We can join tables in snopshots by creating a complex snapshots that will based on the master tables. It is used in Clint-Server and Server-Server communications.
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.
What Is Snapshots? Snapshot is an object used to dynamically replicate data between distribute database at specified time intervals. In ver 7. 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.
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.
Oracle Interview Question and Answers
It should be created before creating snapshots. 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. Tables are completely regenerated using the snapshots query and the master tables every time the snapshot referenced. If simple snapshot used then a snapshot log can be used to send the changes to the snapshot tables.
Default value. If possible it performs a FAST refresh. Otherwise it will perform a complete refresh. What Is A Snapshot Log? A snapshot log is a table in the master database that is associated with the master table. Snapshot logs are used in updating the snapshots based on the master table. 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.
Replication of data in distributed environment. Using snapshots to replicate data. Using remote procedure calls. Differentiate Simple And Complex, Snapshots? A complex snapshots contain atleast any one of the above. 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.
The System Global Area in an Oracle database is the area in memory to facilitate the transfer of information between users. It holds the most recently requested structural information between users. It holds the most recently requested structural information about the database. The structure is database buffers, dictionary cache, redo log buffer and shared pool area. It is area in memory that is used by a single Oracle user process.
What Is A Data Segment? Data segment are the physical areas within a database block in which the data associated with tables and clusters are stored. Due to insufficient shared pool size. Monitor the ratio of the reloads takes place while executing SQL statements. What Is Cluster Key?
The related columns of the tables in a cluster are called the cluster key. Do A View Contain Data? Exist Betw. Report 2. While both reports 2. When-image-activated fires when the operators double clicks on an image item when-image pressed fires when an operator clicks or double clicks on an image item.
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. 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. If there are changes pending in the first form, the operator will be prompted to save them before the new form is loaded.
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.
What Is The Diff? When flex mode is on, reports automatically resizes the parent when the child is resized. When confine mode is on, an object cannot be moved outside its parent in the layout. 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. 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.
Using transactional triggers we can control or modify the default functionality of the oracle forms. Use reports profile executable statement. Use SQL trace facility.
Two group that is above are the left most rank higher than the group that is to right or below it. Tool bar canvas views are used to create tool bars for individual windows.
Oracle DBA Interview Questions & Answers
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. To specify the order of individual group evaluation in a cross products. What Is A Timer? Timer is an "internal time clock" that you can programmatically create to perform an action each time the times. There are two phases of block coordination: 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. There are three most common types of complex master-detail relationships:.
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 undisplayed values. The term is terminal definition file that describes the terminal form which you are using r20run. What Is Use Of Term? The term file which key is correspond to which oracle report functions.
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. The maximum no of chars the parameter can store is only valid for char parameters, which can be upto 64K. No parameters default to 23 Bytes and Date parameter default to 7 Bytes. The default file extensions indicate the library module type and storage format.
The coordination properties are: 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.
Text Parameters and, Data Parameters. Summary, Formula, Placeholder column. Explain About Stacked Canvas Views? 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. Show editor is the generic built-in which accepts any editor name and takes some input string and returns modified output string.
Rep file and, Rdf file. Oracle will stop updating file headers, but will continue to write data to the database files even if a tablespace is in backup mode. In backup mode, Oracle will write out complete changed blocks to the redo log files. Normally only deltas changes are logged to the redo logs. This is done to enable reconstruction of a block if only half of it was backed up split blocks. Because of this, one should notice increased log activity and archiving during on-line backups.
Record group column names cannot exceed 30 characters. 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.
What Are Parameters? 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. Oracle Precompiler exits, Oracle call interface, NonOracle user exits.
Only one window in a form can display the console, and you cannot change the console assignment at runtime. What Is An Administrative privileged User? Oracle DBAs and operators typically use administrative accounts to manage the database and database instance. Control of these privileges is managed outside of the database via password files and special operating system groups. This password file is created with the orapwd utility.
One down repeating frame below one across repeating frame. What Are The Master-detail Triggers? One can select from the SYS.
Modalless windows, Modal windows. What Are Modal Windows? Modal windows are usually used as dialogs, and have restricted functionality compared to modalless windows.
On some platforms for example operators cannot resize, scroll or iconify a modal window. 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. 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.
What Is Lexical Reference? How Can It Be Created? What Is System. It represents the coordination causing event that occur on the master block in master-detail relation. What Is Synchronize? 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. It is a command line argument that allows you to specify a file that contain a set of arguments for r20run. It allows you to read and write information to a file in the file system. In Reports 2. 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.
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. For a modelless window, it determines whether oracle forms hides the window automatically when the operators navigates to an item in the another window.
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. True Or False? 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. A hidden column is used to when a column has to embed into boilerplate text. Canvas views are the back ground objects on which you place the interface items Text items , check boxes, radio groups etc. Each canvas views displayed in a window. Invokes a 3Gl program by name which has been properly linked into your current oracle forms executable.
By using the rectangle tool while pressing the Constraint key. By using the link file property in the layout boiler plate property sheet. By using SRW. Before one import rows into already populated tables, one needs to truncate or drop these tables to get rid of the old data.
If not, the new data will be appended to the existing tables. If the sequences are not dropped, they will generate numbers inconsistent with the rest of the database. Before form , After form , Before report, Between page, After report. Because for each query, report has to open a separate cursor and has to rebind, execute and fetch data.
What Is Coordination Event? Any event that makes a different record in the master block the current record is a coordination causing event.
An Ole server application creates ole Objects that are embedded or linked in ole Containers, ex. OLE containers provide a place to store, display and manipulate objects that are created by ole server applications.
What Is An Object Group? 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. What Is An Lov? An LOV is a scrollable popup window that provides the operator with either a single or multi column selection list. After the query is executed but before the report is executed and the records are displayed. A way in which to pass control and possibly arguments form Oracle report to another Oracle products of 3GL and then return control and back to Oracle reports.
What Is The User-named Editor? 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. 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.
What Is A Record Group? However, unlike database tables, record groups are separate objects that belong to the form module which they are defined. What Is A Property Clause? 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. What Is A Physical 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. This option can be shortened to TERM. This is created using the utlxplan. Once the explain plan table exists you run the explain plan command giving as its argument the SQL statement to be explained. Explain plans can also be run using tkprof.
The tkprof tool is a tuning tool used to determine cpu and execution times for SQL statements. What Is A Cartesian Product? Cartesian product is the result of an unrestricted join of two or more tables.
By use of the exclamation point "! They can be used in exception handling to report, or, store in an error log table, the error that occurred in the code. They can be used to hold values for use in later queries or calculations.Oracle Net Services enable the load balancing of application connections across all of the instances in an Oracle RAC database.
What is use of rollback segments in Oracle database? User Process with associated PGS Oracle can be configured to vary the number of user processes for each server process. What Is Query Execution?