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Download Complete Oracle Interview Questions PDF. Each question contains their answer also. Its a good practice to go through all of these questions before. Here we provide most common interview question and answers for Oracle and and Answers PDF |SQL | SQL SERVER | Latest Oracle Interview Questions and. Oracle interview questions and answers - Oracle FAQ lesforgesdessalles.info - Free download as PDF File .pdf), Text File .txt) or read online for free.
At the time of execute-query post-change trigger will fire, on-validate field trigger will not fire. To specify the order of individual group evaluation in a cross products. For ex: Select the command which is used for character by character substitution. Current Record Attribute is frequently used at the block level to display the current row in a multi-record If you define an item-level Current Record Attribute, you can display a pre-determined item in a special color when it is part of the current record, but you cannot dynamically highlight the current item, as the input focus changes. When Execute-query or count-query Package procedures are invoked.
If any one group fails then database automatically switch over to next group. It degrades performance. Of Rows Per Block? Row size also reduces no of rows per block. Number of times processes repeatedly query the dictionary table is called recursive hints.
It is due to the data dictionary cache is too small. Name of the parameter file to be passed for export. What Is A Logical Backup? Logical backup involves reading a set of database records and writing them into a file. Export utility is used for taking backup and Import utility is used to recover from backup.
It is the set of before image data blocks that contain rows that are modified by a transaction. Each Rollback Segment entry must be completed within one rollback segment.
A single rollback segment can have multiple rollback segment entries. Free extents cannot be merged together in Ver 6. Free extents are periodically coalesces with the neighboring free extent in Ver 7.
For Incremental exports, the flag indirects whether a record will be stores data dictionary tables recording the export. Flag to indicate whether table rows should be exported. If 'N' only DDL statements for the database objects will be created.
Flag to indicate whether export should compress fragmented segments into single extents. What Is Dictionary Cache? Dictionary cache is information about the databse objects stored in a data dictionary table.
What Is A Control File? Database overall physical architecture is maintained in a file called control file. It will be used to maintain internal consistency and guide recovery operations.
Multiple copies of control files are advisable. What Is Database Buffers? ORA decides the size. Make new rollback segment available After shutdown, modify init.
Deactivate Rollback Segment R0 and activate the newly created rollback segments. What Is Cold Backup? Cold backup is taking backup of all physical files after normal shutdown of database. We need to take. Changes made to entries are written to the on-line redo log files. So that they can be used in roll forward operations during database recoveries. Before writing them into the redo log files, they will first brought to redo log buffers in SGA and LGWR will write into files frequently. Calculate the total header size Calculate the available dataspace per data block Calculate the combined column lengths of the average row Calculate the total average row size.
Calculate the average number rows that can fit in a block Calculate the number of blocks and bytes required for the table. A free extent is a collection of continuous free blocks in tablespace.
When a segment is dropped its extents are reallocated and are marked as free. A flag to indicate whether statistical information about the exported objects should be written to export dump file.
A flag to indicate whether rows should be imported. If this is set to 'N' then only DDL for database objects will be executed. A flag to indicate whether indexes on tables will be exported. A flag to indicate whether import should import index on tables or not. A flag to indicate whether grants on databse objects will be exported or not.
Value is 'Y' or 'N'. A flag to indicate whether grants on database objects will be imported. A flag to indicate whether full databse export should be performed. A flag to indicate whether file content should be displayed or not.
A flag to indicate whether constraints on table need to be exported. A flag to indicate whether a read consistent version of all the exported objects should be maintained. When you changes the Existing value to null, the On-validate field trigger will fire post change trigger will not fire. At the time of execute-query post-change trigger will fire, on-validate field trigger will not fire. When Is Pre-query Trigger Executed? When Execute-query or count-query Package procedures are invoked. These triggers are executes when inserting, deleting and updating operations are performed and can be used to change the default function of insert, delete or update respectively.
For Eg, instead of inserting a row in a table an existing row can be updated in the same table. Select the use constraint property is ON Block definition screen. It cannot used in all triggers except key triggers. Pause suspends processing until the operator presses a function key. Pages are collection of display information, such as constant text and graphics. On-validate-field trigger fires, when the field Validation status New or changed.
Post-field-trigger whenever the control leaving form the field, it will fire. INP Source File. FRM Executable File. Function Key Key-function Key-others Key-startup. These keys referred as key F0 through key F9. If one table involved in a statement does not have statistics, Oracle has to revert to rule-based optimization for that statement.
So you really want for all tables to have statistics right away; it won't help much to just have the larger tables analyzed. This can be done by specifying hints. If the index is physically smaller than the table which is usually the case it will take less time to scan the entire index than to scan the entire table. What Enter Package Procedure Does? Enter Validate-data in the current validation unit. The likely cause of this is because the execution plan has changed.
Generate a current explain plan of the offending query and compare it to a previous one that was taken when the query was performing well. Usually the previous plan is not available. Anchor-view Resize -View Move-View. What Is An Alert? An alert is window that appears in the middle of the screen overlaying a portion of the current display. What Is An User Exits? What Is A Trigger? What Is A Package Procedure? Restricted package procedure. Unrestricted package procedure.
Navigational Triggers. Transaction Triggers. When-window-activated, when-window-closed, when-window-deactivated, when-window-resized. When-Image-activated Fires when the operator double clicks on an image Items.
When-image-pressed fires when the operator selects or deselects the image item. What Is A Visual Attribute? Visual Attributes are the font, color and pattern characteristics of objects that operators see and intract with in our application.
Unlimited no of radio buttons can be assigned to a radio group. Create a parameter list to execute the add parameter built-in procedure to add one or more parameters list. What Is A Layout Editor? The Layout Editor is a graphical design facility for creating and arranging items and boilerplate text and graphics objects in your application's interface. List The Types Of Items? Text item. Chart item. Check box.
Display item. Image item. List item. Radio Group. User Area item. What Is A Radio Group? Radio groups display a fixed no of options that are mutually Exclusive. User can select one out of n number of options. Query record group Static record group Non query record group. Page, Page 0? Page - Canvas-View Page 0 - Canvas-view null.
Only when-radio-changed trigger associated with radio group Visual Attributes. Only When-checkbox-activated Trigger associated with a Check box. What Is A List Item? If yes, give the name of the built-in to change the alert messages at run-time. Form Menu Library. Fmb 2.
Mmb 3. Default Block facility. Layout Editor. Menu Editor. Object Lists. Property Sheets. Tables Columns Browser. Built-ins Browser. All other modules provide information to it. If you implement Oracle Financials, you should switch your current GL system first.
GL is relatively easy to implement. You should go live with it first to give your implementation team a chance to be familiar with Oracle Financials. MultiOrg or Multiple Organizations Architecture allows multiple operating units and their relationships to be defined within a single installation of Oracle Applications.
This keeps each operating unit's transaction data separate and secure. A field is a position on a form that one uses to enter, view, update, or delete information. A field prompt describes each field by telling what kind of information appears in the field, or alternatively, what kind of information should be entered in the field. A flexfield is an Oracle Applications field made up of segments. Each segment has an assigned name and a set of valid values.
Oracle Applications uses flexfields to capture information about your organization. There are two types of flexfields: Base table Blocks: A base table block is one that is associated with a specific database table or view. Control Blocks: A control block is a block that is not associated with a database table.
An alert is a modal window that displays a message notifies the operator of some application condition. What Is A Navigable Item? A navigable item is one that operators can navigate to with the keyboard during default navigation, or that Oracle forms can navigate to by executing a navigational built-in procedure. A content view is the "Base" view that occupies the entire content pane of the window in which it is displayed.
A stacked view differs from a content canvas view in that it is not the base view for the window to which it is assigned. What Is A Check Box? A Check Box is a two state control that indicates whether a certain condition or value is on or off, true or false.
The display state of a check box is always either "checked" or "unchecked". What Is A Canvas-view? A canvas-view is the background object on which you layout the interface items text-items, check boxes, radio groups, and so on.
At run-time, operators can see only those items that have been assigned to a specific canvas. Each canvas, in term, must be displayed in a specific window. Database Triggers. There are two types of cursors, Implicit Cursor and Explicit Cursor. User defined cursors are called Explicit Cursors. They can be declared and used. Package Specification contains declarations that are global to the packages and local to the schema.
Package Body contains actual procedures and local declaration of the procedures and cursor declarations. This ensures that users only have access to data that pertains to them. Using this option, one could even store multiple companies' data within the same schema, without them knowing about it. Select from SYS. What Is Oracle Label Security? Access to rows are restricted according to a user's security sensitivity tag or label. What Is Oem oracle Enterprise Manager?
OEM is a set of systems management tools provided by Oracle Corporation for managing the Oracle environment. It provides tools to monitor the Oracle environment and automate tasks both one-time and repetitive in nature to take database administration a step closer to "Lights Out" management.
It is not possible. In the standard package. Return datatype is local variable declarations Begin executable statements Exception execution handlers End;. Function is called as part of an expression. Extensibility,Modularity, Reusability, Maintainability and one time compilation. What Is An Exception?
What Are Types Of Exception? The types are Predefined and user defined. Some of Predefined exceptions are. What Is A Database Trigger? Usages are Audit data modifications, Log events transparently, Enforce complex business rules Derive column values automatically, Implement complex security authorizations. Maintain replicate tables. What Is A Cursor? Why Cursor Is Required? Cursor is a named private SQL area from where information can be accessed. Cursors are required to process rows individually for queries returning multiple rows.
A function can not be called.
What Is A Stored Procedure? A stored procedure is a sequence of statements that perform specific function. A cursor declared in a package specification is global and can be accessed by other procedures or procedures in a package. A cursor declared in a procedure is local to the procedure that can not be accessed by other procedures. True if rows are fetched. True if no rows are featched.
Procedures and Functions,Packages and Database Triggers. Increased functionality for example,global package variables can be declared and used by any proecdure in the package and performance for example all objects of the package are parsed compiled, and loaded into memory once.
Database triggers can be used to automatic data generation, audit data modifications, enforce complex Integrity constraints, and customize complex security authorizations. What Is A Procedure? What Is A Package? A Package is a collection of related procedures, functions, variables and other package constructs together as a unit in the database. A Function returns a value to the caller where as a Procedure does not. What Is Database Trigger? What Are Oracle Precompilers?
The output must be compiled and linked with this library to creator an executable. The variables declared in the procedure and which are passed, as arguments are called actual, the parameters in the procedure declaration. Actual parameters contain the values that are passed to a procedure and receive results.
Formal parameters are the placeholders for the values of actual parameters. The return type for a cursor must be a record type. Its a command line tool that allows user to type SQL commands to be executed directly against an Oracle database.
Self join -Its a join foreign key of a table references the same table. Outer Join --Its a join condition used where One can query all the rows of one of the tables in the join condition even though they don't satisfy the join condition. Equi-join -Its a join condition that retrieves rows from one or more tables in which one or more columns in one table are equal to one or more columns in the second table. The processing done in a fetch loop modifies the rows that have been retrieved by the cursor.
A convenient way of modifying the rows is done by a method with two parts: Rename is a permanent name given to a table or column whereas Alias is a temporary name given to a table or column which do not exist once the SQL statement is executed. However,queries that return more than one row you must declare an explicit cursor or use a cursor FOR loop. IS statement.
INTO statements. What Is A Outer Join? Outer Join: Oracle does not allow a user to specifically locate tables, since that is a part of the function of the RDBMS. What Is Oci. What Are Its Uses? Oracle Call Interface is a method of accesing database from a 3GL program.
The OCI library provides. Why It Is Required? Odd number of records: If Yes How. If Not Why? INTO statements when the where clause of the querydoes not match any rows. There Is A String 12 0. INSTR ' 12 0. Form trigger FT Fires when user presses a key or navigates between fields on the screen.
Can be row level or statement level No distinction between row level and statement level. Can manipulate data stored in Oracle tables via SQL Can manipulate data in Oracle tables as well as variables in forms. Can be fired from any session executing the triggering DML statements. Can be fired only from the form that define the trigger. Can cause other database triggers to fire. Can cause other database triggers to fire, but not other form triggers. Cursor For Loop is a loop where oracle implicitly declares a loop variable, the loop index that of the same record type as the cursor's record.
How It Is Defined? A cursor variable is associated with different statements at run time, which can hold different values at run time. Static cursors can only be associated with one run time query. A cursor variable is reference type like a pointer in C. Declaring a cursor variable: What Are Cursor Attributes?
What Is On Delete Cascade? Deleted records can be rolled back or committed. What Is A Transaction? Transaction is logical unit between two commits and commit and rollback. To protect some of the columns of a table from other users. To hide complexity of a query. To hide complexity of calculations. What Is The Subquery? Sub query is a query whose return values are used in filtering conditions of the main query.
Only if you access next value in the session, current value can be accessed. It enables rolling back part of a transaction. Maximum of five save points are allowed. ROWID is a pseudo column attached to each row of a table. Explain Connect By Prior?
Retrieves rows in hierarchical order. Only one LONG column is allowed. What Is Referential Integrity? Maintaining data integrity through a set of rules that restrict the values of one or more columns of the tables based on the values of primary key or unique key of the referenced table.
What Is A Join? Join is a query which retrieves related columns or rows from multiple tables. What Is An Integrity Constraint? Integrity constraint is a rule that restricts values to a column in a table. Remember to setup a backup for the repository database after creating it.
What Is A Database Link? Database Link is a named path through which a remote database can be accessed. CYCLE specifies that the sequence continues to generate values after reaching either maximum or minimum value. After pan ascending sequence reaches its maximum value, it generates its minimum value. After a descending sequence reaches its minimum, it generates its maximum. What Is Correlated Sub-query? Correlated sub query is a sub query which has reference to the main query. CHAR pads blank spaces to the maximum length.
If Yes Under What Conditions? Either rman or alter tablespace begin backup will do. There are basically 6 types of sql statments. They are. According to ANSI, a transaction begins with first executable statement and ends when it is explicitly committed or rolled back.
Procedures do not Return values while Functions return one. One Value Packages:: Packages Provide a method of encapsulating and storing related procedures, functions, variables and other Package Contents. There are Three Integrity Rules.
They are as follows The various Master and Detail Relationship are. The various Block Coordination Properties are. Snapshots are mirror or replicas of tables. Views are built using the columns from one or more tables. The Single Table View can be updated but the view with multi table cannot be updated. Oracle does implement the OOPS concepts.
The best example is the Property Classes. We can categorize the properties by setting the visual attributes and then attach the property classes for the objects. OOPS supports the concepts of objects and classes and we can consider the property classes as classes and the items as objects. Candidate keys are the columns in the table that could be the primary keys and the primary key is the key that has been selected to identify the rows.
Unique key is also useful for identifying the distinct rows in the table. What Is Concurrency? Concurrency is allowing simultaneous access of same data by different users.
Locks useful for accesing the database are. What Are Previleges And Grants? Previleges are the right to execute a particulare type of SQL statements. Right to Connect, Right to create, Right to resource Grants are given to the objects so that the object might be accessed accordingly. Physical Storage Of The Data? The finest level of granularity of the data base are the data blocks. Data Block:: One Data Block correspond to specific number of physical database space.
Extent is the number of specific number of contigious data blocks. Set of Extents allocated for Extents. There are three types of Segments a Data Segment:: Non Clustered Table has data segment data of every table is stored in cluster data segment. Each Index has index segment that stores data. Temporarily store 'undo' information. Pct Free is used to denote the percentage of the free space that is to be left when creating a table.
Similarly Pct Used is used to denote the percentage of the used space that is to be used when creating a table eg Pctfree 20, Pctused What Is Row Chaining? The data of a row in a table may not be able to fit the same data block. Data for row is stored in a chain of data blocks. What Is A 2 Phase Commit? Two Phase commit is used in distributed data base systems.
This is useful to maintain the integrity of the database so that all the users see the same values. There are basically 2 phases in a 2 phase commit. Deleting a table will not remove the rows from the table but entry is there in the database dictionary and it can be retrieved But truncating a table deletes it completely and it cannot be retrieved. What Are Mutating Tables? When a table is in state of transition it is said to be mutating.
If a row has been deleted then the table is said to be mutating and no operations can be done on the table except select.
What Are Codd Rules? What Is Normalisation? Normalisation is the process of organising the tables to remove the redundancy. There are mainly 5 Normalisation rules. A post query will fire for every row that is fetched but the pre query will fire only once.
We can delete the duplicate rows in the table by using the Rowid. Can U Disable Database Trigger? What Is Pseudo Columns? Name Them? A pseudocolumn behaves like a table column, but is not actually stored in the table. You can select from pseudocolumns, but you cannot insert, update, or delete their values. This section describes these pseudocolumns:. The number of columns in a table can range from 1 to What Is Clustered Index?
In an indexed cluster, rows are stored together based on their cluster key values. Can not applied for HASH. What Are Attributes Of Cursor? What Are Object Groups? An object group is a container for a group of objects. You define an object group when you want to package related objects so you can copy or reference them in another module.
What Are Referenced Objects? Referencing allows you to create objects that inherit their functionality and appearance from other objects. Referencing an object is similar to copying an object, except that the resulting reference object maintains a link to its source object.
A reference object automatically inherits any changes that have been made to the source object when you open or regenerate the module that contains the reference object.
Is Forms 4. What Is Secure Property? Hides characters that the operator types into the text item. This setting is typically used for password protection. What Are Property Classes? Can Property Classes Have Trigger? Property class inheritance is a powerful feature that allows you to quickly define objects that conform to your own interface and functionality standards. Property classes also allow you to make global changes to applications quickly.
By simply changing the definition of a property class, you can change the definition of all objects that inherit properties from that class.
All type of triggers. Which Will Fire First? Item level trigger fires , If item level trigger fires, property level trigger won't fire. Triggers at the lowest level are always given the first preference. The item level trigger fires first and then the block and then the Form level trigger. What Are Alerts? When Mouse Navigate is True the default , Oracle Forms performs standard navigation to move the focus to the item when the operator activates the item with the mouse.
When Mouse Navigate is set to False, Oracle Forms does not perform navigation and the resulting validation to move to the item when an operator activates the item with the mouse. This property is useful for calling a form from another one. What Are Timers? When When-timer-expired Does Not Fire? The When-Timer-Expired trigger can not fire during trigger, navigation, or transaction processing. Yes , object group can have block as well as program units.
There are 2 types of canvases called as Content and Stack Canvas. Content canvas is the default and the one that is used mostly for giving the base effect. Its like a plate on which we add items and stacked canvas is used for giving 3 dimensional effect. What Are User-exits? A user exit is a C subroutine written by you and called by Oracle Forms to do special-purpose processing.
When called by an Oracle Forms V3 trigger, the user exit runs, then returns a status code to Oracle Forms. Your exit can display messages on the Oracle Forms status line, get and set field values, do high-speed computations and table lookups, and manipulate Oracle data.
You obtain a return value from a foreign function by assigning the return value to an Oracle Forms variable or item. Make sure that the Oracle Forms variable or item is the same data type as the return value from the foreign function. What Is Iapxtb Structure? What Is Precompiler? Specifies whether Oracle Forms should issue savepoints during a session. What Is Transactional Trigger Property? Identifies a block as transactional control block.
What Is Ole Automation? What Does Invoke Built-in Do? What Is Call Form Stack? Yes we can port applications across platforms. Consider the form developed in a windows system. Which Trigger Related To Mouse? Specifies the named visual attribute used when an item is part of the current record. Current Record Attribute is frequently used at the block level to display the current row in a multi-record If you define an item-level Current Record Attribute, you can display a pre-determined item in a special color when it is part of the current record, but you cannot dynamically highlight the current item, as the input focus changes.
You can programmatically change an object's named visual attribute setting to change the font, color, and pattern of the object at runtime. Change windows registry regedit. What Is Log Switch? The point at which ORACLE ends writing to one online redo log file and begins writing to another is called a log switch. What Is On-line Redo Log? The On-line Redo Log is a set of two or more on-line redo files that record all committed changes made to the database.
Whenever a transaction is committed, the corresponding redo entries temporarily stores in redo log buffers of the SGA are written to an on-line redo log file by the background process LGWR. The on-line redo log files are used in cyclical fashion. Start an instance, Mount the Database and Open the Database. Rolling forward to recover data that has not been recorded in data files, yet has been recorded in the on-line redo log, including the contents of rollback segments.
Rolling back transactions that have been explicitly rolled back or have not been committed as indicated by the rollback segments regenerated in step a. Releasing any resources locks held by transactions in process at the time of the failure.
Resolving any pending distributed transactions undergoing a two-phase commit at the time of the instance failure. 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. What Is Archived Redo Log? Archived Redo Log consists of Redo Log files that have archived before being reused. Specifies whether the window is a Document window or a Dialog window.
Specifies the event that will activate the OLE containing item. Specifies the mouse cursor style. Use this property to dynamically change the shape of the cursor. Formula columns:: For doing mathematical calculations and returning one value.
Summary Columns:: For doing summary calculations such as summations etc. Place holder Columns:: These columns are useful for storing the value in a variable. It is possible to have more than one layout in a report by using the additional layout option in the layout editor. By using the lock option we cannot move the fields in the layout editor outside the frame. This is useful for maintaining the fields. Flex is the property of moving the related fields together by setting the flex property on.
The minimum number of groups required for a matrix report are 4 e What Is A Sequence? What Is A Segment? A segment is a set of extents allocated for a certain logical structure. Describe Referential Integrity? A rule defined on a column or set of columns in one table that allows the insert or update of a row only if the value for the column or set of columns the dependent value matches a value in a column of a related table the referenced value.
It also specifies the type of data manipulation allowed on referenced data and the action to be performed on dependent data as a result of any action on referenced data.
What Is Hash Cluster? A row is stored in a hash cluster based on the result of applying a hash function to the row's cluster key value. All rows with the same hash key value are stores together on disk. What Is A Private Synonyms? A Private Synonyms can be accessed only by the owner. What Is Database Link? A database link is a named object that describes a "path" from one database to another.
When Can Hash Cluster Used? Hash clusters are better choice when a table is often queried with equality queries. For such queries the specified cluster key value is hashed. The resulting hash key value points directly to the area on disk that stores the specified rows. What Is Private Database Link? Private database link is created on behalf of a specific user. A private database link can be used only when the owner of the link specifies a global object name in a SQL statement or in the definition of the owner's views or procedures.
What Is Public Database Link? A public database link can be used when any user in the associated database specifies a global object name in a SQL statement or object definition. What Is Network Database Link? Network database link is created and managed by a network domain service. A network database link can be used when any user of any database in the network specifies a global object name in a SQL statement or object definition.
What Is Data Block? Oracle database's data is stored in data blocks. One data block corresponds to a specific number of bytes of physical database space on disk. 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. An extent is a specific number of contiguous data blocks, obtained in a single allocation and used to store a specific type of information.
Data segment, index segment, rollback segment and temporary segment. Each index has an index segment that stores all of its data. A database contains one or more rollback segments to temporarily store "undo" information. To generate read-consistent database information during database recovery and to rollback uncommitted transactions by the users. What Is A Temporary Segment? Temporary segments are created by Oracle when a SQL statement needs a temporary work area to complete execution.
When the statement finishes execution, the temporary segment extents are released to the system for future use. What Is A Datafile? Every Oracle database has one or more physical data files.
A database's data files contain all the database data. The data of logical database structures such as tables and indexes is physically stored in the data files allocated for a database.
The set of redo log files for a database is collectively known as the database redo log. The primary function of the redo log is to record all changes made to data. The information in a redo log file is used only to recover the database from a system or media failure prevents database data from being written to a database's data files. Database name Names and locations of a database's files and redolog files. Time stamp of database creation. 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.
A hot backup is basically taking a backup of the database while it is still up and running and it must be in archive log mode. A cold backup is taking a backup of the database while it is shut down and does not require being in archive log mode. The benefit of taking a hot backup is that the database is still available for use while the backup is occurring and you can recover the database to any point in time.
The benefit of taking a cold backup is that it is typically easier to administer the backup and recovery process. In addition, since you are taking cold backups the database does not require being in archive log mode and thus there will be a slight performance gain as the database is not cutting archive logs to disk.
I would create a text based backup control file, stipulating where on disk all the data files where and then issue the recover command with the using backup control file clause. A data block is the smallest unit of logical storage for a database object. As objects grow they take chunks of additional storage that are composed of contiguous data blocks. These groupings of contiguous data blocks are called extents.
All the extents that an object takes when grouped together are considered the segment of the database object. 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.
Fact tables and dimension tables. A fact table contains measurements while dimension tables will contain data that will help describe the fact tables. Disable the foreign key constraint to the parent, drop the table, re-create the table, enable the foreign key constraint.
Alter database backup control file to trace. Instance startup. Explain An Ora? You get this error when you get a snapshot too old within rollback.
It can usually be solved by increasing the undo retention or increasing the size of rollbacks. You should also look at the logic involved in the application getting the error message. 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? Here is a list of 60 interview questions about Oracle Database with their answers. The list contains questions useful for basic, freshers and experienced oracle professionals. Each question contains their answer also.
Its a good practice to go through all of these questions before attending the interview. Its main areas of specialization include developing and marketing database software and technology, enterprise software products and cloud engineered systems. Oracle was second to Microsoft in terms of the highest revenue generation by a software making company in The company equally designs and develops tools used in database development and middle-tier software systems, enterprise resource planning ERP software, software for supply chain management SCM , and software for customer relationship management CRM.
Are you preparing to attend an Oracle interview soon? Here are a few questions and answers you may find interesting. RAW data type is used in storing values in binary data format. The maximum size of a RAW in a table is bytes. A BLOB data type is a binary string with a varying length which is used in storing two gigabytes memory.
NULL value represents unknown or missing data. It is used as a place holder or represented as a default entry indicating that no actual data is present.