Dbms Hindi

Database Management Systems

DATABASE MANAGEMENT SYSTEMS UNIT – I Operational data, Purpose of database system, Views of data, Data models: Relational, Network, Hierarchical, Instances & Schemes, Data Dictionary, Types of Database languages: DDL, DML, Structures of a DBMS, Advantages & Disadvantages of a DBMS, 3- Level Architecture Proposal: External, Conceptual & Internal Levels, Entity Relationship Model as a tool of conceptual & Internal Levels, Entity Relationship Model as a tool of conceptual set, Attributes, Mapping Constraints, Keys, Entity-Relationship diagram (E-R diagram) : Strong & weak entities, Generalization, Specialization, Aggregation, Reducing ER diagram to tables UNIT – II Set theory concepts and fundamentals: Relations, Domains, Attributes, Tuple, Concepts of Keys: Candidate key, Primary Key, Alternate Key, Super Key, Foreign Key, Fundamental integrity rules: Entity integrity, Referential integrity, Extension & Intention, Relational Algebra : Select, Project, Cross product, Different types of joins i.e. theta join, equi join, natural join, outer join, set operations. Structure query language (SQL), Codd's rules. UNIT – III Functional Dependencies, Good & Bad Decomposition, Anomalies as a database: A consequences of bad design, Universal Relation, Normalization: First, Second, Third & BCNF Normal Forms, Multivalues Dependency, Join Dependency & forth Fifth Normal Form. UNIT – IV Basic Concepts – INDEXING & HASHING, Indexing: B+ tree Index Files, B-tree Index Files, Hashing : Static has functions, Dynamic Hash Functions, Index Definition in SQL : Multiple key Access. UNIT – V Failure Classification, The Storage Hierarchy, Transaction Model, Log Based Recovery, Buffer Management, Shadow Paging

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Database Management Systems Bachelor of Computer Application (BCA) Examination, December 2005 2BCA3 - DATA BASE MANAGEMENT SYSTEM Unit I 1. gkfLiVy dk ,d E-R ekMy cukb;s ftlesa MkWDVj yksxksa dk ,d leqPp; gks vkSj jkfx;ksa dk ,d leqPp; gks] izR;sd jksxh dk VsLV jksxksa ds lkFk Association n’kkZb,A Draw an E-R diagram for the database of hospital with a seat of patients and set of a Medical Doctors with each patients a log of the various tests conducted is also associated. 20 2. ¼v½ Recursive lEcU/k dk D;k eryc gSa \ dqN mnkgj.k nsdj le>kb;sA What is meant by a Recursive relationship type? Give some examples of recursive relationship types. 10 ¼c½ nks Record based MkVk ekMy ds ykHk o gkfu dks ifjyf{kr dhft,A State the major advantage and disadvantage of the two record base data models. 10 Unit II 3. fuEu dh O;k[;k dhft,% ¼v½ lqij dh ¼c½ izkFkfed dh ¼l½ fjys’ku ,ytsczk esa Økl izksMsDV ¼n½ izktsDV vkijs’kuA Describe the following: (a) Super Key (b) Primary Ke (c) Cross Product in Relational Algebra (d) Project Operation. 20 4. ,l- D;w- ,y- ls vki D;k le>rs gks \ mnkgj.k lfgr SQL dh O;k[;k dhft,A What do you mean by S.Q.L.? Describe the SQL with example. 20 Unit III 5. fuEufyf[kr dh O;k[;k dhft,% Explain the following: (a) Tuple Entity (b) Normalization (c) Codd Rule (d) Universal Relation. 20 6. ¼v½ pkSFks (4 NF) vkSj ikapos (5 NF) esa dkSu&dkSu ls phtsa dkWeu gSa \ What are common factor in fourth and fifth normal form? 10 ¼c½ fuEu Relation }kjk larq"V dh tkus okyh lHkh Functional dependencies crkb,% List all functional dependencies satisfied by the following relation: A B C a1 b1 c1 a1 b1 c2 a2 b1 c1 a2 b1 c2 Unit IV 7. B+ Vªh ij mnkgj.k lfgr ,d fucU/k fyf[k,A Write an essay on B+ tree with suitable example. 20 8. B- Vªh bUMsDl Qkby D;k gS \ mnkgj.k lfgr Mkbukfed gSl QaD’ku dh O;k[;k dhft,A What is B-tree index files? Describe Dynamic Hash Function with an example. 20 Unit V 9. ¼v½ Buffer Management D;k gS \ What is Buffer Management? ¼c½ fMLd [kjkc gksus ds mijkUr dksbZ Recovery Procedure crkb;sA Explain a recovery procedure that is needed after a disk crash. 10 10. ¼v½ MkVkcsl ds Transaction Model dh O;k[;k dhft,A Describe the Transaction Model of Database. 10 ¼c½ Failure Classification ds dqN egRoiw.kZ igywvksa dh O;k[;k dhft,A Describe some important features of failure classification. 10

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Database Management Systems Database Mangement system Interelated Data rFkk ml Data dks Access djus ds fy, fy[ks x;s Programs dk lewg gSa fdlh Hkh ,d Enterprise ls Related Data ds collection dks Database dgk tkrk gSaA DBMS dk izeq[k mn~ns'; Database Information dks lgh rFkk Convenient :i ls Store djuk gSaA Database System Application: - Database dbZ txg ij iz;ksx esa yh tkrh gSaA vr% mlds fuEu Application gSaA (1) Banking ds fy, Use dh tkrh gSaA (2) Airline Reservation rFkk Information dk Schedule cukus ds fy,A (3) Universities esa Students ds Information rFkk course ds ckjs esa iwjh tkudkjh nsus ds fy,A (4) Monthly Satement dks cukus ds fy,A (5) Telecommunication ds fy,A (6) Finance esa Sales rFkk Purchase dh Information dks Store djukA (7) Sales esa Customer Product o Purchase Information dks j[kukA (8) Manufacturing esa Management ds Supply rFkk Warehouse o Order dh Information dks Store djukA (9) Human Resources ds vUrxZr Employee, salary, payroll, tax vkfn Information dks Store djukA Database System Vs File System: - File System esa Data dks Store djds Operating System ij Store fd;k tkrk gSaA System Permanent Records dks dbZ Files esa j[krs gSa rFkk fdlh File ls Record izkIr djuk rFkk u;s record dks tksM+us ds fy, vyx&vyx izdkj ds Application Program dks Use djuk iM+rk gSaA DBMS ls igys Systems blh izdkj dh files esa Data dks Store djds j[krs Fks ijUrq DBMS }kjk file system ds Disadvantages dks nwj fd;k x;k o ;gh DBMS ds Advantage gksrs gSaA (1)Data Reduandancy ds dkj.k vf/kd Storage o vf/kd Access Cost yxrh gSaSA Same Data dh Various Copies dh j[kus ls ,d le; esa lHkh dks ,d lkFk Update ugha fd;k tk ldrkA blh leL;k dks Data Inconsistency dgk tkrk gSaA (2) Difficulting in Accessing Data:- Data dks Access o Retrieve djus esa dfBukbZ u gks blds fy, fofHkUu Application Programs dks mi;ksx esa fy;k tkrk gSaA (3) Data Isolation:- Data o Processor dks ,d lkFk j[kus ls Application Programs ds }kjk vklkuh ls Data dks Access fd;k tk ldrk gSaA (4) Integrity Problem:- Data dks dqN Condition ds vk/kkj ij ,d lkFk DBMS esa j[kk tkrk gSaA (5) Atomicity Problem:- Computer System Mechanical o Electrical gksus ds dkj.k Faliure Occur gks ldrk gSaA ;fn Faliure Occur gks tk, rks MkVk dks MkVkcsl aRestore djuk vko’;d gksrk gSaA bls gh Atomicity dgk tkrk gSaA (6) Security:- gj User Database ds MkVk dks Access ugha dj ldrk gSaA flQZ MkVkcsl ds ,d ikVZ dks Access fd;k tk ldrk gSaA View of Data:- Database dk ,d y{; Users dks MkVk dk Abstract View Provide djuk gSa blesa system dh Details dks Hide fd;k tkrk gSaA ftlls MkVk dks fdl rjg Store o Maintain fd;k tk, Hkh ifjHkkf"kr fd;k tkrk gSaA Data Abstraction:- vr% MkVk dk laf{kIrhdj.k gh MkVk Abstraction dgykrk gsaA Database Users Computer Trained ugha gksrsA vr% Developers ds }kjk MkVkcal dh tfVyrk dks Users ls dj fn;k tkrk gSaA vr% laf{kIrhdj.k ds fuEu Level dks define fd;k x;k gSaA (1) Physical Level:- ;g Abstraction dk lcls Lower Level gSa tks ;g ifjHkkf"kr djrk gSa fd MkVk dks okLro esa fdl izdkj LVksj fd;k tk,A Physical Level Data Structure Detail dh tfVyrk dks ifjHkkf"kr djrk gSaA (2) Logical Level:- Abstraction dk vxyk level ;g ifjHkkf"kr djrk gSa fd Database esa D;k Data Store djuk gsa rFkk MkVk ds chp ds Relationship dks Maintain djukA (3) View Level:- ;g Abstraction dk lcls mijh ysoy gSa tks flQZ Part of the Database dks ifjHkkf"kr djrk gSaA

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Database Management Systems

View level View1

View2

ViewN

Logic level

Instances & Schema:- Information dk og Collection ftls fdlh {k.k MkVkcsl esa LVksj fd;k tkrk gSa mls Database Instance dgrs gSaA MkVkcsl dh iwjh Design dks MkVkcsl Schema dgk tkrk gSaA Schema dks Abstraction Levels ds vk/kkj ij ckaVk x;k gSa%& (1) Physical Schema:- ;g Physical Level dh MkVkcsl design dks ifjHkkf"kr djrk gSaA (2) Logical Level Schema:- blesa Logical Level dh fMtkbu dks ifjHkkf"kr fd;k tkrk gSaA View Level ij Hkh MkVkcsl ds cgqr ls Define fd;k tkrk gSa ftls Subschema dgrs gSaA ftlesa Database ds Different Views dks define fd;k x;k gSaA Data Models:- Database Structure gh Data Model gSaA Data esa laca/k] Consistency Constraint o MkVk ds dkYifud Tools dks ifjHkkf"kr djuk gh Data Models ds eq[; dk;Z gSaA fuEu Data Models dks define fd;k x;k gSa%& (1) E-R Models (2) Relational Model (3) Object Oriented Data Model (4) Object Relational Data Model (5) Network Data Model (6) Hierarchical Data Model (1) E-R Model:- os Real World Objects ftUgsa vU; Objects ls differentiate fd;k tk ldrk gSa] mUgsa Entity dgrs gSaA Entities dks Attributes ds Li esa Database esa ifjHkkf"kr fd;k tkrk gSaA tSls A/c Number, A/c Balance vkfn Attributes gSa ftls Account Entity esa define fd;k x;k gSaA fofHkUu Entities ds e/; laca/k LFkkfir djuk gh Relationship dgykrh gSaA Database ds Logical Structure dks E-R diagram ds }kjk ifjHkkf"kr fd;k x;k gSa%& (1) Rectangles ( )- Entity Set dks iznf’kZr fd;k tkrk gSaA (2) Ellipse ( ) – blesa Attributes dks iznf’kZr fd;k tkrk gSaA (3) Diamonds ( ):- blds }kjk Entity Set ds e/; Relationship dks lsV fd;k tkrk gSaA (4) Lines (-):- Entity Set o Entity dks tksM+us ds fy;s Lines dks mi;ksx esa fy;k tkrk gSaA Customer name

Cust-ID

Customer Street

Account Number

Balance

Customer City

Account

Customer Depositor

E-R Model esa fuEu Attributes dks ifjHkkf"kr fd;k x;k gSa%& (1) Simple Value Attribute (2) Compsite Value Attribute (3) Single Value Attribute (4) Derived Attribute Developed By SMS (The best friends group) 4 Keen College Bikener (College of IT & Management) Ph. 9785306009,9983850627,9269069945

Database Management Systems

(1) Simple Attributes:- Simple Attributes dks Parts ¼vU; Hkkxksa½ esa fofHkUu ugha fd;k tk ldrkA Example:- Loan Number, Amount vkfnA (2) Composite Value Attributes:- Composite Attributes os Attributes gSa ftUgsa Sbparts esa Devide ¼foHkDr½ fd;k tk ldrk gSaA tSls%& Name ,d Composite Attribute gSa tSls%& First name, Middle Name o Cost Name vkfnA (3) Single Value Attribute:- ;s Attributes ftudh Value ges’kk ,d gh jgrh gSa tSls%& ,d Customer ;fn cgqr ls yksu ysrk gSa rks Loan No. ges’kk vyx&vyx gksxsaA vr% ;g ,d Single Value Attribute gSaA (4) Multi valued Attribute:- tc fdlh Attribute dh ,d ls T;knk Values gks rks mls Multivalue Attribute dgk tkrk gSaA tSls%& Phone Number Multi value Attribute gSa D;ksafd ,d Customer ds ,d ls T;nk (0,1,2,………n) Phone Numbers gks ldrs gSaA (5) Derived Attribute:- bl izdkj ds Attributes dks fofHkUu vU; Attributes ls Derive fd;k x;k gSaA tSls ;fn ,d Customer us cgqr ls yksu ys j[ks gSa rks og irk yxk;k tk ldrk gSa fd Customer us Bank ls fdruk yksu fy;k gSaA Relationship & Relationship Set:- fofHkUu Entities ds e/; laca/k LFkkfir djuk gks Relationship dgykrh gSaA tSls Customer Table dk yksu Vscy ls lacaf/kr gksukA Same Type ds Relations dks ,d lkFk ,df=r dj j[kuk gh Relationship Set dgykrk gSa tSls nks Entity Set Customer o yksu ds e/; Borrower Relationship gSa tks Customer o yksu ds e/; Relationship dks iznf’kZr djrk gSaA fdlh Hkh Entity Set dh Primary Key ds }kjk fofHkUu Entity Set dks vU; Entity Set ls i`Fkd fd;k tk ldrk gSaA (2) Relational Model ¼fjys’kuy ekWMy½:- Relational Model Tables dk Collection gSa ftlesa Data rFkk Relationship dks iznf’kZr fd;k tkrk gSaA gj Vscy esa Multiple Columns rFkk gj Column dk ,d vyx uke gksrk gSaA Relational Model dks Record Based Model dk ,d mnkgj.k Hkh ekuk tkrk gSa D;ksafd blesa Records dks Fixed Format esa LVksj fd;k tkrk gSaA Relational Model dk abstraction level E-R Model dh vis{kk Lower gksrk gSaA Database dks igys E-R Model ds :i esa Design fd;k tkrk gSaA ckn esa mls Relational Model esa Translate dj fn;k tkrk gSaA (3) Object Oriented Data Model:- bls E-R Model dk Extension Hkh dgk tkrk gSa ftleas Encapsulation ¼lHkh MkVk tks Related gks dks ,d lkFk j[kuk½ Methods ¼ftlls Database ls MkVk dks Access fd;k tk lds½ o Object Identity (Object dh igpku) dks ifjHkkf"kr fd;k tkrk gSaA E-R Model dh ,d Entity dks Object dgk tkrk gSaA tc MkVk rFkk mls Access djus ds Methods dks ,d lkFk Single Unit esa j[kk tkrk gSa rks bls Object Oriented Model dh ,d Property Encapsulation dgk tkrk gSaA ftlds Contents dks ckgjh rRoksa }kjk ugha ns[kk tk ldrkA (4) Object Relational Data Model:- Object Relational Data Model esa Object Oriented Data Model o Relational Data Model nksuksa dks 'kkfey fd;k tkrk gSaA Data Dictionary:- Data Dictionary esa Meta data (Data About Data) dks j[kk tkrk gSaA Table dh Design Metadata dk gh ,d mnkgj.k gSaA Data Dictionary esa fuEu Information dks LVksj fd;k tkrk gSaA (1) Name of the Relation (Relation dk uke) (2) Names of the Attributes of Each Relation (Relation ds gj Attributes dk uke) (3) Length of Attributes (Attribute dh yEckbZ) (4) Integrity Constraints ¼MsVk dks ,d lkFk j[kus ds fy;s miyC/k 'krsZ½ cgqr ls lhLVe esa User ls laca/khr MkVk dks Hkh LVksj fd;k tkrk gSa tSls%& (1) Name of The Authorized User (2) User ls laca/khr Accounts dks lwpuk Developed By SMS (The best friends group) 5 Keen College Bikener (College of IT & Management) Ph. 9785306009,9983850627,9269069945

Database Management Systems (3) Password ;k vU; lwpuk,aA Database Languages:- Database ds }kjk fuEu nks Hkk"kkvksa dks iz;ksx esa fy;k tkrk gSa%& (1) DDL:- Database Design o mlls laca/khr fofHkUu ifjHkk"kkvksa ds laxzg dks ,d Special Hkk"kk ds }kjk iznf’kZr fd;k tkrk gSa ftls DDl dgrs gSaA Create Table Account mnkjg.k ds fy;s%& (a/c_number valchar(20), balance number (4) mijksDr Statement ds }kjk a/c Table dks Create fd;k x;k gSaA blds (DDl) }kjk Data dicitionary dks Hkh Update fd;k tk ldrk gSaA tc fdlh Hkh MkVk dks Read ;k Modify djuk gks rks Database System lcls igys Data Dictionary dks pSd djrk gSaA MkVkcsl dk Storage Structure o Access Method dks ,d Special DDL esa j[kk tkrk gSa ftls Data Storage and definition Language (DSDL) dgk tkrk gSa ;s Information User ls Nqih jgrh gSaA Data Manipulation Language (DML):- Data Manipulation dk vFkZ gSa%& (1) Database esa Store Information dks Access djukA (2) u;h Information dks MkVkcsl dks LVksj djukA (3) MkVkcsl dks mifLFkr Information dks Delete djukA (4) Database esa mifLFkr Information dks Modify djukA DML dks eq[;r% nks Hkkxksa esa ck¡Vk x;k gSa%& (1) Procedural DML (2) Declaration DML (1) Procedural DML dh vko’;drk user dks blfy;s gksrh gSa D;ksafd ;g user dks fdlh Data dh vko’;drk gSa o ml MkVk dks dSls Access fd;k tk ldrk gSaA ds ckjs esa crkrh gSaA (2) Declaration DML:- mls Non Procedural DML Hkh dgk tkrk gSa D;ksafd blesa flQZ MkVk dh vko’;drk dks iznf’kZr fd;k tkrk gSa ijUrq ;g define ugha fd;k tkrk fd MkVk dks fdl izdkj Access fd;k tk,A Database dks Information dks Access djus ds fy;s Query dks mi;ksx esa fy;k tkrk gSaA DML dk og Hkkx tks lwpuk dks Relational ds fy;s mi;ksx esa fy;k tkrk gSa mls Query Language dgk tkrk gSaA Database System Structure:- Database System dh Modules esa foHkkftr fd;k x;k gSa rFkk gj Module ij System Control ls laca/khr ftEesnkjh gksrh gSaA Database System dks Functionally nks Hkkxksa esa foHkkftr fd;k x;k gSa%& (1) Storage Manager (2) Query Processor Components (1) Storage Manager:- Storage Manager Program dk og Module gSa tks Low Level Data rFkk Application Programs o Queries ds e/; Interaction djrk gSaA Storage Manager File System Commands esa ifjofrZr djus dk dk;Z Hkh djrk gsaA vr% Storage Manager Data ds Relational o Updation ds fy;s mÙkjnk;h gksrk gSaA Storage Manager esa fuEu rRoksa dks 'kkfey fd;k tkrk gSa%& (1) Authorization and Integrity Manager:- blesa MkVk ds Integrity Constraints rFkk Users dh Authority dh Hkh pSd fd;k tkrk gSaA (2) Transaction Manger:- ;g Database dh Ensistancy ds fy;s mÙkjnk;h gksrk gSa rFkk Transaction dks yxkrkj fcuk O;o/kku Execute djus dk dk;Z Hkh djrk gSaA (3) File Manager:- blds }kjk Disk Space o MkVk Structure dks iznf’kZr fd;k tkrk gSaA (4) Buffer Manager:- Data dks Main Memory esa ykus ds fy;s mÙkjnk;h gksrk gSaA Storage Manager ds }kjk fofHkUu Data Structure dks Implement fd;k tkrk gSa%& (1) Data files:- ftlesa Data Store jgrk gSaA (2) Data Dictionary:- ftlesa Data About Data dks j[kk tkrk gSaA (3) Indices:- blesa MkVk dks Fast Access fd;k tk ldrk gSaA Developed By SMS (The best friends group) 6 Keen College Bikener (College of IT & Management) Ph. 9785306009,9983850627,9269069945

Database Management Systems (2) Query Processor:- Query Processor Components dks Include fd;k x;k gSa%& (1) DDL Interpreter:- tks DDL Statement dks Interpreter djrk gSa rFkk mu Statement dh ijhHkk"kk dks Data Dictionary esa Store djrk gSaA (2) DMl Compiler:- ;g DML Statements dks Low-level Instruction esa ifjofrZr djus dk dk;Z djrk gSaA (3) Query Evaluation Engine:- ;g DML Compiler }kjk Generated Low-Level Instruction dks Execute djus dk dk;Z djrk gSaA Native /naiveUs ers Use

Application Programmer

Sophisticated Users

Write

Application Interface

Use

Application Programs

Application Program Object Code

Use

Query Tools

Compiler & Linker

DML Queries

Administrator Tools

DDL Interpreter

DML Compiler & Organizer

Query Evaluation Engine

Buffer Manager

Database Aministrator

Query Processor

File Manager

Authorization Integrity Manager

Transaction Manager

Storage Manager

Indices Data

Data Dictionary Statistical Data

Disk Storage

Index

Application Architecture:- Database Applications dks nks Hkkxksa esa foHkDr fd;k x;k gSa%& (1) Two Tier Architecture (2) Three Tier Architecture (1) Two Tier Architecture:- blesa Application dks Component esa ck¡Vk tkrk gSa ftls Client Machine ij j[kk tkrk gSaA bl Component }kjk Database System dh Functionality dks Server Machine ij Query Language dh lgk;rk ls Access fd;k tkrk gSaA Client o Server ds e/; Interactoin dk dk;Z ODBC (Open Database Connectivity) ;k JDBC (JAVA Database Connectivity) }kjk fd;k tkrk gSaA Developed By SMS (The best friends group) 7 Keen College Bikener (College of IT & Management) Ph. 9785306009,9983850627,9269069945

Database Management Systems

USER

USER Client

Application

Application Network

Network Database System

Server

APPLICATION SERVER

Database

System 2-Tier Architecture 3-Tier Architecture

(2) 3- Tier Architecture:- blesa Client Machine dh Front end ds :i esa iz;ksx esa fy;k tkrk gS rFkk ;g e’khu Directly Database Calls dks ugha j[krhA Client e’khu forms ds }kjk Application Server ls Internet djrh gSaA Application Server ckn esa Database dks Database dks Access djrk gSaA cM+h Application ds fy;s Three-tier dh mi;qDr jgrk gSaA ftls www (World Wide Web) ij ju fd;k tk ldrk gSaA ADVANTAGES & DISADVANTAGES OF DBMS ADVANTAGES %& (1) Redundancy Control:- DBMS ds }kjk gj Logical Data Item dks ,d txg LVksj fd;k tkrk gSa ftlls Information dh vusd Copies ugha curh o T;knk Storage Space Hkh ugha yxrk gSaA ftlls T;knk Updation dh Problem Hkh ugha vkrhA (2) Access Control:- Database Administrator lqj{kk (Security) o Authorization dks mi;ksx ds fy;s miyC/k djokrk gSa vr% DBA ;k Data rFkk User nksuks ij iwjk Control gksrk gSaA (3) Program Object rFkk Data Structure ds fy;s iw.kZ LVksjst%& Objects ftUgsa Database esas Store fd;k tkrk gSa ;s Program Execution rFkk Transmination ds fy;s mÙkjnk;h gksrk gSA Database esa mifLFkr MkVk dks ckj&ckj dbZ User }kjk mi;ksx esa fy;k tk ldrk gSaA (4) Multiple User Interface:- gj User Database ls vius Lo;a ds izksxzke o Interface ds vk/kkj ij Interact djrk gSa bu Interface dks fofHkUu izksxzkfeax Hkk"kkvksa esa develop fd;k tk ldrk gSaA ijUrq mudk Database ls Compalible gksuk vko’;d gSaA (5) Data dks Enter djus ds fy;s DBMS }kjk cgqr lh lhekvksa dks ifjHkkf"kr fd;k tkrk gSa rFkk bUgsa Process }kjk mi;ksx Hkh fd;k tkrk gSaA (6) Backup & Recovery:- DBMS Faliure ds dkj.k dbZ ckj Problem esa vk tkrk gSa] ijUrq DBMS }kjk Faliure (Hardware ;k Software) ls Recover gksus ds Hkh dbZ lk/ku miyC/k gSa ftlesa MkVk dks Inconsistent Data esa vkus ls cpk;k tk ldrk gSaA (7) Data Sharing:- ge tkurs gSa fd DBMS esa MkVk dh flQZ ,d gh dkWih LVksj gksrh gSa blh dkWih dks cgqr ls Users }kjk mi;ksx esa fy;k tkrk gSaA (8) Data Abstraction dk xq.k gksus ds dkj.k MkVkcsl ds Structure dks fcuk Users dks ijs’kku ;k Disturb fd;s Modification fd;k tk ldrk gSaA (9) Database gj le; Users dks Latest Information Provide djrk gSaA

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Database Management Systems DISADVANTAGES:(1) Database System ds fy;s izkjfEHkd Investment vf/kd gksrk gSa ftlesa Hardware Software o vU; Trainings Hkh 'kkehy gksrh gSaA vxj Cost High gks rks nwljk rjhdk