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
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 a1 a2 a2 b1 b1 b1 b1 c1 c2 c1 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
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 gSaSaA 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 aaaRestore 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
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
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
View1 View2 ViewN
View level
Logic level
Cust-ID
Customer name Customer Street
Customer City Customer Depositor Account Account Number Balance
(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
(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
mnkjg.k ds fy;s%& Create Table Account
(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) 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
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
Native /naiveUs ers Application Programmer Sophisticated Users Database Aministrator Application Interface Application Programs Query Tools Administrator Tools
Use Write Use Use
Compiler & Linker DML Queries DDL Interpreter Application Program Object Code DML Compiler & Organizer Query Evaluation Engine Query Processor Buffer Manager File Manager Authorization Integrity Manager Transaction Manager Storage Manager Data Dictionary Statistical Data Indices Data Disk Storage Index
(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 gSaa 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
USER Application Client USER Application Database System APPLICATION SERVER Database System Network Network Server 2-Tier Architecture 3-Tier Architecture
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 <w¡< ysuk pkfg;sA
(2) DBMS ds lkFk vU; mifjO;;ksa tSls Security Concurrency Control, Recovery rFkk Integrity Constriants vkfn dks Hkh 'kkfey djuk vko’;d gksrk gSaA
(3) dqN ifjfLFkfr;k¡ ftlesa Database rFkk mu ij mi;ksx yh tkus okyh Application Simple gks rFkk ,d yEcs le; rd ;fn mls Change u djuk gks rks DBMS dk iw.kZ mi;ksx ugha fd;k tk,xkA rFkk mlds dqN Features dks mi;ksx esa ugha fy;k tkrkA
(4) dHkh&2 Database System dks Sigle User ds fy;s gh cuk;k tkrk gSaA blds fy;s Hkh DBMS Suitable ugha gSaA MPPING CONSTRAINTS:- Enitity rFkk Relationship dks fuEu lhekvksa ds vUrxZr ifjHkkf"kr fd;k tkrk gSa%&
(1) MAPPING CARDINALITIES ¼esfiax dkMZusfyfV½ (2) Participation Constraints ¼ikfVZflis’ku dUlVªsaV½
(1) MAPPING CARDINALITY:- bUgsa 4 Hkkxksa esa ck¡Vk x;k gSa%&
(1) One to One:- Entity A vf/kd ls vf/kd B dh ,d Entity ls Connected gks rFkk B dh ,d Entity vf/kd ls vf/kd A dh ,d Entity ls laca/khr gksA
ONE to ONE
(2) One to Many:- A dh ,d Entity b dh cgqr lh Entity ls laca/khr gks ldrh gSaA ijUrq b dh ,d Entity vf/kd ls vf/kd A dh ,d Entity ls gh laca/khr gks ldrh gSaA
One to Many
(3) Many to One:- A dh ,d Entity vf/kd ls vf/kd B dh ,d Entity ls laca/khr gks ldrh gSaA ijUrq B dh ,d Entity A dh cgqr lh Entities ls laca/khr gks ldrh gSaA
Many to One
(4) Many to Many:- A dh vusd Entities B dh vusd Entities ls laca/khr gks ldrh gSa] mlh izdkj B dh vusd Entities A dh vusd Entities ls laca/khr gks ldrh gSaA
Many to Many a1 a2 a3 b1 b2 b3 a1 a2 a3 b1 b2 b3 b4 b5 a1 a2 a3 a4 a5 b1 b2 b4 a1 a2 a3 a4 b1 b2 b3 b4
KEYS:-
(1) Super Key:- Super Key ,d ;k ,d ls vf/kd Attributes dk lewg gSa ftlls fdlh Entity Set dks Uniquely fd;k tk ldrk gSA tSls Customer Table ftlesa (Customer ID, Customer Name, Customer City) vkfn gSa ds fy;s Customer_id Super Key gSa D;ksafd blls Customer Table dks Uniquly Identify fd;k tk ldrk gSaA mlh izdkj (Customer_id + Customer_name, Customer_id _ Customer_city) Hkh Super Key gSa D;ksafd buls Hkh Customer Table dks Uniquely Identify fd;k tk ldrk gSaA ijUrq Customer name, Customer City dks Super Key ugha ekuk tk ldrk D;ksafd Customer dk uke ;k Customer dh City Same gks ldrh gSaA
(2) Candidate Key:- Super dh dk Concept User ds fy;s i;kZIr ugha gksrk gSaA D;ksafd Super Key esa dqN Extra Attributes dks Hkh 'kkfey fd;k tkrk gSaA vr% Super Key dk Minimisation djuk Candidate Key dgykrh gSaA Customer_name o Customer Street nksuksa Attributes ds }kjk Customer Table ds Record dks Uniquely identify fd;k tk ldrk gSaA vr% Customer_id o Customer name + Customer_Street nksuks Candidate Key gksxhA ijUrq Customer name, Customer City o Customer_id dk Combination Candidate Key ugha gksrk gSaA (3) Primary Key:- Candidate Key esa ls fdlh ,d Key dks as a Primary Key Choose dj fy;k tkrk gSaA ¼ijUrq ;g ckr /;ku j[kuh vko’;d gksrh gSa fd Primary Key esa dHkh Hkh Null Value½ dks Conidor ugha fd;k tkrk gSaA vr% Primary Key esa Null Value gks ldrh gSaA
(4) Composite Key:- dHkh&2 Relation ;k Table esa dksbZ Hkh ,d Key ugha gksrh ftls Primary Key cuk;k tk ldsA vr% nks Attributes dks bdV~Bk dj mls Primary Key cuk;k tkrk gSa mls Comosite Key dgrs gSaA
(5) Foreign Key:- tc fdlh ,d Table dh Primary Key dks nwljh Table esa Hkh iznf’kZr djuk gks rks nwljh Table esa og Primary Key Attribute Foreign Key dgykrk gSaA
E-R Diagram:- E-R Diagram ds }kjk MkVkcsl ds Logical Structure dks Graphically iznf’kZr fd;k tkrk gSaA E-R Model ds dqN rRo fuEu gSa%&
(1) Rectangles:- ( ) Entity Set dks blds }kjk iznf’kZr fd;k tkrk gSaA (2) Ellipses:- ( ) blds }kjk Attributes dks iznf’kZr fd;k tkrk gSaA
(3) Diamonds:- ( ):- blds }kjk Relationship Set dks iznf’kZr fd;k tkrk gSaA
(4) Lines:- (&&):- Entity o Entity Set ds chp esa Relationship dks Link ds }kjk iznf’kZr fd;k tkrk gSaA (5) Double Ellipses ( ):- Multi value Attributes dks iznf’kZr fd;k tkrk gSaA
(6) Dashed Ellipses ( ):- blds }kjk derived Attributes dks iznf’kZr fd;k tkrk gSaA
(7) Double Rectangles:- ( ):- Weak Entity Set dks Double Rectangle ds }kjk iznf’kZr fd;k tkrk gSaA E-R Diagram ds }kjk Mapping Eardinality dks Hkh iznf’kZr fd;k tk ldrk gSaA
(1) One to One:- iznf’kZr djus ds fy, ( ) dks mi;ksx esa ysrs gSaA (2) One to Many:- iznf’kZr djus ds fy, ( ) dks mi;ksx esa ysrs gSaA (3) Many to One:- iznf’kZr djus ds fy, ( ) dks mi;ksx esa ysrs gSaA (4) Many to Many:- iznf’kZr djus ds fy, ( ) dks mi;ksx esa ysrs gSaA
One to One Cust-ID Customer_name Customer_Street Customer_City Customer Borrower Loan Loan Number Amount
One to Many
Many to One
Many to Many
STRONG & WEAK ENTITY SET:- dqN ,sls Entity Set gksrs gSa ftuesa Primary Key dks Define gh ugha fd;k tk ldrkA bl izdkj ds Entity Set dks Weak Entity Set dgrs gSaA
ijUrq tc fdlh Entity Set esa Primary Key dks define fd;k tkrk gSa rks mls Strong Entity Set dgrs gSaA
Weak Entity Set dks Meaning ful cukus ds fy;s mls fdlh nwljh Entity ls dusDV fd;k tkrk gSaA ml Entity Set dks Identity ;k Owner Entity Set dgk tkrk gSa rFkk og Weak Entity Set Owner Entity Set ij dependent gksrk gSaA Generalization:- Database design Process dks Bottom up /kkj.kk esa Hkh cuk;k tk ldrk gSa ftlesa Multiple Entity Sets dks higher Level Entity Set esa muds Common Features ds vk/kkj ij ifjofrZr dj fn;k tkrk gSaA
Agreegation:- blesa fdlh Database Retrieval Process esas No. of Inputs ds vk/kkj ij Single Output Generate fd;k tkrk gSa tSls ;fn dEiuh esa dke djus okys Employees dh Gross Salary fudkyuh gSa rks No. of Inputs eas lHkh Employees dh Dalary vk,xh rFkk mldk Output ,d vFkkZr~ Gross Salary gksxkA
Reducing E-R diagrams into Tables:- (E-R Diagram dks Vscy esa ifjofrZ djuk)
E-R Database Schema dks Group of Table esa j[kk tk ldrk gSaA Database ds gj Entity Set o Relationship Set dks ,d vyx Vscy esa Store fd;k tkrk gSa] o mls ,d vyx uke ls ifjHkkf"kr djrs gSaA
Cust-ID Customer_name Customer_Street Customer_City Customer Borrower Loan Loan Number Amount Cust-ID Customer_name Customer_Street Customer_City Customer Borrower Loan Loan Number Amount Cust-ID Customer_name Customer_Street Customer_City Customer Borrower Loan Loan Number Amount
E-R Model rFkk Relation Model nksuks gh Relation World Entities dks iznf’kZr djrs gSaA vr% nks Model tks ,d ls design Principles dks Follow djrs gSa vr% E-R Design dks Relational Design esa ifjofrZr dj fn;k tkrk gSaA
CUSTOMER
NAME CUST_ID ADDRESS CITY
RAM 404 M.G. ROAD JODHPUR
(1) E-R Diagram ls ifjofrZr Vscy dks Relation dgrs gSaA (2) Table ds Colums dks Attributes dgk tkrk gSaA (3) ,d Record dks Tuple dgrs gSaA
(4) fdlh Attributes esa mifLFkr Value dks Domain dgrs gSaA
Relation
Attributes Tuple Domain
UNIT-II
Integrity Rules:- Integrity Constrains ds }kjk ;g Ensure fd;k tkrk gSa fd Authorized Users ds }kjk tc MkVkcsl esa dqN cnyko fd;s tkrs gSa rks mlls MkVkcsl esa Inconsistency Maintain ugha gksrhA
“Integrity Constraints ls eq[; rkRi;Z ;g gSa fd Data dks dqN lhekvksa ds vUrxZr ,d lkFk j[kuk ftlls MkVkcsl esa Consistency cuh jgsaA
Integrity Constraints dks eq[;r% 4 Hkkxksa eas ckaVk x;k gSa%& (1) Domain Integrity
(2) Entity Integrity (3) Referential Integrity (4) User defined Integrity
(1) Domain Integrity:- Data Base ds fdlh Relation esa fdlh Attribute esa Insert dh xbZ Value dks Domain dgk tkrk gSaA vr% fdlh Hkh Attribute esa Data dh Possible Value dks Insert djuk gh Domain Integrity dgykrk gSaA ;fn fdlh Record ds Particular Domain esa Value ugha Mkyh xbZ gSa rks mlesa Value dks Insert dj fn;k tkrk gSaA (2) Entity Integrity:- lHkh Real World Objects dks Entity dgk tkrk gSa o gj Entity ,d nwljs ls vyx gksrh gSaA tc fdlh ,d Entity Set dh Entity esa ,d gh Data Type dh Values fd;k tkrk gSa rks mls Entity Integrity dgk tkrk gSaA
(3) Referential Integrity:- Referential Integrity Foreign Key ij fuHkZj djrh gSaA tc fdlh Vscy dh Primary Key Attribute dks fdlh nwljh Vscy esa Hkh Consider fd;k tkrk gSa rks nwljh Vscy esa ogh Attribute Foreign Key Attribute dgykrk gSaA vr% nksuks Relation ds Key Attributes dh Value Hkh leku gksuh pkfg,A bl izdkj ds Constraint ¼lhek½ dks Referential Integrity dgk tkrk gSaA
(4) User Defined Integrity:- mijksDr Integrity Constraints ds vykok User dqN vU; Integrity Constraints dks Hkh Database ij Implement dgk tkrk gSaA tSls Database esa fdlh Hkh Record dks Insert djus ds fy;s 1st Letter dks
Capital fy[kuk vkfnA
RELATIONAL ALGEBRA
(1) Relation Algebra Procedural Query Language gSaA
(2) blesa Input ds :i esa ,d ;k nks Relation dks fy;k tkrk gSa o Result ds :i esa ,d u;k Relation curk gSaA (3) Relational Algebra ds eq[; Operations Select, Project, Union, Set Difference o Cartesian Product
gSaA
FUNDAMENTAL OPERATION OF RELATIONAL ALGEBRA:-
(1) Select Project Operations dks Unary Operation dgk tkrk gSa D;ksafd os flQZ ,d Relation ij Operation Perform djrs gSaA
(2) vU; rhu Operations Union, Set difference o Cartesian Product dks Binary Operations dgk tkrk gSa D;ksafd bUgsa Perform djus ds fy, nks Relations dh vko’;drk gSaA
(1) Select Operation:- Select Operation ds }kjk nh xbZ Condition ds vk/kkj ij Topless dks Select fd;k tkrk gSaA Selection ds fy;s xzhd Letter Sigma dks mi;ksx esa fy;k tkrk gSa Slect Operation ds lkFk =, #, <, <, >, > vkfnA Operation dh Hkh mi;ksx esa fy;k tk ldrk gSaA
Selection Operation ds lkFk Logical Operation Perform djus ds fy;s Logical Operator dks mi;ksx esa fy;k tkrk gSaA blds fy;s and(^), or (v), Not (¬) Symbol dks mi;ksx esa ysrs gSaA
Example:-
(1) Loan Relation esa ls Delhi Branch ds Records dks lysDV djukA branch-name = ‘Delhi’ (LOAN)
(2) Loan Relation esa ls mu Records dks Select djuk ftudk Amount >1200 gksA Amount >1200 (LOAN)
(3) Loan Relation esa ls mu Records dks Select djuk ftudk Amount >1200 o Branch delhi gksA branch-name = ‘Delhi’ ^ Amount >1200 (LOAN)
(2) Project Operation :- ;fn Selected Data dh List dks Display djuk gks rks Project dks mi;ksx esa fy;k tkrk gSa blds fy;s xzhd Letter (∏) dks mi;ksx esa ysrs gSaA
Example:-
(1) 10 and Relation esa ls Loan no o Amount Attributes dks Display djukA ∏ Loan No., amount (Loan)
COMBINATION OF SELECT & PROJECT:-
(1) fdlh Hkh Relation dh Information dks Condition ds lkFk Display djus ds fy;s Select o Project nksuks Operations dks mi;ksx esa fy;k tkrk gSaA
tSls%& mu Customers dh Information dks Display djuk tks Delhi Brach esa jgrs gSaA ∏Customer_name (Branch_name = ‘Delhi’(Customer))
CARTESIAN PRODUCT OPERATION:- Cartesian Product Operation dh x }kjk denote fd;k tkrk gSa ;g Binary Operation gSa ftlesa nks Relation ij Operations Perform fd;s tkrs gSa bl Operation dks Perform fuEu nks Condition esa fd;k tk ldrk gSaA
(1) nksuks Relation ftl ij Cartesian Product Perform djuk gSa esa dksbZ ,d Column Same gksu vko’;d gSaA (2) nksuks Table esa ,d Column leku gksrk gSa rks mls Relation Name o Dot (.) Operator }kjk vyx vyx fd;k
tk ldrk gSaA
Cartesian Product dk Result Records ds Product ds :i esa vkrk gSaA tSls ;fn ,d Relation esa 4 Records o nwljs esa 5 Records gSa rks Result ds :i esa (5x4) = 20 Records dh Display fd;k tk,xkA
Cartesian Product dks fuEu izdkj Perform fd;k tk,xkA
Relation 1 Relation 2 1 5 2 6 3 7 4 8 Relation1 × Relation2 (1,5), (1,6), (1,7), (1,8), (2,5), (2,6), (2,7), (2,8), (3,5), (3,6), (3,7), (3,8), (4,5), (4,6), (4,7), (4,8)
Example:- ;fn mu lHkh Customers ds uke dks Find Out djuk gSa ftUgksus Delhi Branch ls loan fy;k gSa rks blds fy;s fuEu Relation Algebra Query dks fy;k tk,xkA
∏
cust _name( branch_name = ‘Delhi’ (borrower X loan))SET OPERATIONS:-
(1) Union Operations:- Relational Algebra esa Union Operation dh (U) ds }kjk denote fd;k tkrk gSaA Union Operation esa nks Relation dks ,d Relation dh rjg Display fd;k tkrk gSa lkFk gh Relation esa mifLFkr Duplicates dks Hkh Remove dj fn;k tkrk gSaA
tc nks Relation ij Union (U) Operation dks Perform fd;k tkrk gSa] rks Union ,d Relation Display djrk gSa ftlesa R1 Relation ds o R2 Relation ds lHkh Tuples gksrs gSa ijUrq duplicates dks Remove dj fn;k tkrk gSaA Example:- ;fn Bank ds mu lHkh Customer dh List dks Display djuk gSa ftudk Bank esa Account gks ;k ftlesa Bank ls Loan ys j[kk gks ;k nksuksa rks blds fy;s fuEu Query dks Perform fd;k tk,xk%&
∏
customer_name (borrower) U∏
customer_name (depositor)Union Operation Perform djus ds fy;s fuEu nks ckrksa dks /;ku esa j[kuk vko’;d gSa%& (1) nksuks Relations esa Same Number of Attributes dk gksuk vko’;d gSaA
(2) Intersection:- Relational Algebra esa Intersection Operation dks (∩) ds }kjk denote fd;k tkrk gSaA blesa Hkh duplicates dks Remove dj fn;k tkrk gSaA
tc nks Relation ij Intersection (∩) Operation Perform fd;k tkrk gSa] rks Intersection ,d Relation Display djrk gSa ftlesa Relation R1 ds os Records tks Relation R2 esa Hkh mifLFkr gks (Common) dks Display fd;k tkrk gSaA Example:- ;fn Bank ds mu Customer dks Find Out djuk gks ftudk cSad esa ,dkmUV Hkh gks o ftUgksaus cSad ls yksu Hkh ys j[kk gksA
∏
customer_name (borrower) ∩Customer_name (depositor)(3) SET- Difference:- Relation Algebra esa Set Difference Operation dks (-) ds }kjk denote fd;k tkrk gSa blesa Hkh duplicates dks Remove fd;k tkrk gSaA
tc nks Relation ij Set difference Operation dks Apply djrs gSa rks blesa Result ds :i ea mu Records dks Display fd;k tkrk gSa tks R1 Relation esa rks gSa ijUrq R2 Relation esa ughaA
Example:- cSad ds lHkh Customer Name dh List dks Display djuk ftldk Bank esa Account gks ij mlus cSad ls yksu ugha fy;k gSa rks blds fy;s fuEu Query dh tk,xhA
∏
customer_name (depositor) -∏
customer_name (borrower)SQL:- (Structured Query Language):- SQL dks San Jose Laboratory esa IBM }kjk developed fd;k x;k FkkA SQL dks cgqr ls Parts ls feydj cuk;k x;k gSa%&
(1) DDL (Data Definition Language):- SQL DDL ds }kjk Relation Rchema dks define, delete o Modify djus ds Commands dks Provide djok;k tkrk gSaA
(2) Interactive DML (Data Manipulation Language):- blesa Tuples dks Insert, delete o Modify djus ds Commands dks Insert fd;k tkrk gSaA
(3) View Definition:- View define djus ds fy;s SQL DDL esa Commands dks Store fd;k tkrk gSaA
(4) Transaction Control:- Transaction dh Beginning o Ending esa Hkh SQL Commands dks Include fd;k tkrk gSaA
(5) Authorization:- Relation o View dks Access djus ds fy;s Login Password fn;s tkrs gSaA
Relation Database Relations dk Collection gSa ftlesa gj Relation dks Unique name fn;k tkrk gSa Data base esa Unknown Values ds Insertion dks jksdus ds fy;s Null Values dks Insert fd;k tkrk gSaA
SQL dk Basic Structure rhu Clauses ij fuHkZj djrk gSa%& (1) Select (2) From (3) Where • Select Operation Relational Algebra ds (
π
) Projection Operation dh rjg gSaA • From Clause Relational Algebra ds Cartesian Product ds leku gSaA (x)• Where Clause Relational Algebra ds Selected ( ) Operation dh rjg gSaA (1) Select Clause:- Select Clause ds }kjk Records dks Display fd;k tkrk gSaA
Example:- ;fn Loan Relation ls lHkh Branch_name dks Display djokuk gSa rks fuEu Query dh tk,xh%& Select branch_name
From loan
;fn Relation esa ls duplicates dks Rename djuk gks rks distinct Keyword dks Select fd;k tkrk gSaA Select distinct branch_name
From Loan
(2) Where Clause:- Where Clause esa Relation ls lacaf/kr Conditions dks fy[kk tkrk gSaA
Example:- ;fn Loan Relation esa ls mu Records dks Select djuk gSa tks delhi branch ls gSa o ftudk Amount 3000 ls vf/kd gSa rks blds fy;s fuEu Query Perform dh tk,xh%&
select loan_no. from Loan
Where Clause ds :i Relation Operator (>, <, >, <, =, #) vkfn dks rFkk Logical Operator (and, or, not) dks Hkh mi;ksx esa fy;k tkrk gSaA
Codd’s Rules:- E.F. Ted Codd’s ds }kjk Functional Database Management System ij Rules fufeZr fd;s x;s gSa tks fuEu gSa%&
(1) Relation Database Management:- RDBMS }kjk flQZ Information dh Relational Capabilities dks Manage fd;k tkrk gSaA
(2) Information Representation:- lHkh Information ftls Relation Database }kj iznf’kZr fd;k tkrk gSa mUgsa Data Item Values ds :i eas Store fd;k tkrk gSa ;s lHkh Data Items Table esa Store jgrs gSaA
(3) Logical Accessibility:- gj Relation ds Data Item dh Value dks Access djus ds fy;s table dk uke] Column o Primary Key Value dks define fd;k tkrk gSaA
(4) Representation of Null Values:- DBMS ds }kjk Null Values dks Hkh iznf’kZr fd;k tkrk gSaA Numeric Values ds fy;s Null Value 0 ;k dksbZ vU; digit gksrk gSa o Character ds fy;s Null Value Blank Space ;k dksbZ vU; Character Value gksrh gSaA
(5) Data Language:- RDBMS ds }kjk Data o Database Accessing Language dh ifjHkkf"kr fd;k tkrk gSaA (6) Insert, Update & Delete:- fdlh Hkh Operation ds }kjk Database esa Values dks Insert Updates o
Delete fd;k tk ldrk gSaA
(7) Physical data Independence:- tc Physical Storage Representation ;k Access Methods dks Change fd;k tkrk gSa rks Application Programs esa Change dh vko’;drk ugha gksrhA
(8) Integrity Constraints:- DBMS esa Data Languages ds }kjk Entity o Referential Integrity dks define fd;k x;k gSaA
(9) Data Distribution:- DBMS ds fy;s ftu Database Languages dks cuk;k x;k gSa muls distribute Database ij Change fd;s tk ldrs gSaA
(10) No Subversion:- DBMS User ds }kjk ,d leku flQZ ,d Row ij Operation Perform fd;k tkrk gSa ftlls Entity o Referential Integrity Constraints dh Hkh lqj{kk gksrh gSaA
JOINS
Natural Join:- tc fdlh Query ij Cartesian Product Perform fd;k tkrk gSa rks bl Cartesian Product Perform fd;k tkrk gSa rks bl Product ds Result ds ckn ml ij Selection Condition dks Apply fd;k tkrk gSaA tSls%& ;fn Bank ds mu lHkh Customers dh List dks Display djuk gSa ftUgksaus Bank ls Loan ys j[kk gSa o lHkh Loan No. o Loan Amount dks Hkh Display djuk gSa rks blds fy, lcls igys Borrower o Loan Relation ij Cartesian Product Perform fd;k tk,xk ckn esa Same Loan Number okys Tuples dks Select fd;k tk,xkA blds fy;s fuEu Query Perform dh tk,xh%&
π
customer_name, Loan_number, Amount (borrower) Loan_number = Loan, Loan_number (borrower X Loan)bl leL;k dks nwj djus ds fy, Natural Join Operation Perform fd;k tkrk gSa ftlesa Selection o Cartesian Product dks ,d Operation esa ifjofrZr dj fn;k tkrk gSaA bls Symbol }kjk iznf’kZr fd;k tkrk gSaA
π
customer_name, Loan_number, cannot (borrower Loan)Outer Join:- Outer Join Operation Join Operation dk Extension gSa ftlesa Missing Information dks Hkh Display fd;k tkrk gSaA tSls%& ;fn gekjs ikl nks Relation gSa%&
Employee (Employee_name, Street, city) Works (Employee_name, branch_name, Salary)
vc ;fn bu ij Natural Join Operation Perform fd;k tkrk gSa] lk nksuks Relation esa ls Employee name ds vk/kkj ij Selection fd;k tk,xkA ;fn ,d Relation esa ,d vU; Employee_name gSa tks nwljs esa ugha gSa rks ml Information dks Display ugha fd;k tk,xkA
bl Loss Of Information dks Explain djus ds fy;s o Remove djus ds fy;s Outer Join Operation & Perform fd;k tkrk gSaA
Outer Join Operation dks 3 Hkkxksa esa ck¡Vk x;k gSa%& (1) Left Outer Join
(2) Right Outer Join (3) Full Outer Join
(1) Left Outer Join esa left Relation ds mu lHkh Tuples dks Display fd;k tkrk gSa tks Right Relation dks match ugha gksrsA vr% tks Tuples Right Relation esa ugha gSa ogk¡ ij Null Values dks Insert fd;k tkrk gSaA vr% Left Relation dh lkjh Information izkIr gksrh gSaA
(2) Right Outer Join esa Right Relation ds mu lHkh Tuples dks Display fd;k tkrk gSa tks Left Relation ls Match ugha gksrsA vr% tks Tuples Left Relation esa ugha gSa ogk¡ ij Null Values dks Insert dj fn;k tkrk gSaA vr% Right Relation dh lkjh Information izkIr gksrh gSaA
(3) Full Outer Join esa Right o Left Relation ds Unmatched Operation o tuples dks 'kkfey dj Display fd;k tkrk gSa o Null Value Insert dj nh tkrh gSaA
UNIT-III
Functional Dependencies %&
(1) bl dependency ds }kjk Bad Database Design dks Good Database Design esa ifjofrZr fd;k tkrk gSaA (2) Functional Dependency ,d ,slh Key gSa ftlds }kjk Database ij Generalization fd;k tkrk gSaA
(3) fdlh Hkh Relation esa Attribute A, Attribute B ij rHkh fuHkZj djrk gSa tc B dh gj Value ds fy;s A dh Exactiy ,d Value gksA
(4) Attribute B, ftl ij Attribute A depend djrk gSa mls determinant dgk tkrk gSaA (5) Functional Dependency dks nks izdkj ls mi;ksx fy;k tk ldrk gSa%&
(1) Relation (table) dh lHkh vko’;d Functional dependency dks Check djukA
(2) Relations in dqN vko’;d Limitations ds fy;s Hkh Functional dependency dks mi;ksx esa fy;k tkrk gSaA
Example:- ,d Relation Employee ftlesa fuEu Attributes dks 'kkfey fd;k x;k gSaA Employee = {Ecode, Name, City}
EMPLOYEE Ecode Name City
E1 A1 Delhi
E2 A2 Calcutta
E3 A3 Madras
mijksDr Employee Table esa gj Ecode ds fy;s Name dh Exact ,d Value ds fy;s gSaA vr% ;g dgk tk ldrk gSa fd Name Ecode ij Functionally dependent gSaA vr% Ecode dks determinant dgk tkrk gSaA vr% Ecode ds vk/kkj in Name o City nksuksa dks Access fd;k tk ldrk gSaA
Normalization dk iwjk Concept Functional dependency ij fuHkZj djrk gSaA Relational Database Design dh dfe;k¡ fuEu gSa%&
Bad Database design esa fuEu dfe;ksa dks iznf’kZr fd;k tkrk gS%& (1) Repetetion of Information
(2) Information dks dHkh&2 iwjh rjg ls iznf’kZr ugha fd;k tkrkA (3) Database esa Insertion ds le; vkus okyh leL;k gSA (4) Database esa deletion ds le; vkus okyh Problem:-
bu lHkh leL;kvksa dks Database ls gVkus ds fy;s Relation dks NksVs&2 Hkkxksa esa ck¡Vdj u;s Relation cuk;s tkrs gSa ftlls fdlh Hkh izdkj dk Information Loss u gkaA bl izdkj dh fof/k;ksa dks decomposition Tecniques dgk tkrk gSa ;k Loss-less Join dgk tkrk gSa ;k Lossy decomposition dgk tkrk gSaA
tSls ,d Relation R gSa tc Database Anomalies ¼dfe;ksa½ dks nwj djus ds fy;s NksVs&2 Hkkxksa esa ck¡Vk tkrk gSa rks%& R = {r1 U r2 U r3 ………. U rn}
;k
R = {r1 U r2 U r3 ………. U rn}
vr% tc lHkh decomposed Relation dks feyk;k tkrk gSa rks iqu% Relation R curk gSa o fdlh Hkh Information dk loss ugha gksrk gSaA
UNIVERSAL RELATION APPROACH:- Database Design ds le; Single Relation dks ysdj mlesa lHkh vko’;d Attributes dks mi;ksx esa ys fy;k tkrk gSaA rFkk ckn esa bl Relation dks NksVs&2 Hkkxksa esa (Relation) esa foHkDr dj fn;k tkrk gSaA Decomposition dk eq[; mn~ns’; Information Loss dks u gksus nsuk gSaA
Example:- ,d Loan Relation esa fuEu Attributes dks ifjHkkf"kr fd;k x;k gSa%& Loan:- (i) Branch Name, Loan Number
(ii) Loan_number, Amount
mijksDr rhu decomposed Relation gSaA blesa ls (i) Relation esa Loan Amount dks Store ugha fd;k x;k gSa rks bl izdkj ds Records dks danling Records o tuples dks dangling Tuples dgk tkrk gSa D;ksafd tc Hkh bu rhuksa Tables dks Join djds data Access fd;k tk,xk rc Record Information v/kwjh izkIr gksxh D;ksafd Loan Amount dks Insert ugha fd;k x;k gSaA blds fy;s Record Information dks [kkyh u j[kdj Null Value dks Insert dj fn;k tkrk gSa rFkk bl izdkj ds Relations dks Universal Relation dgk tkrk gSaA ¼;wfuolZy½ vr% Null Value dks fcuk Database esa fdlh Hkh Unknown Value dks Insert ugha fd;k tkrkA
NORMALIZATION:- Normalization ,d oSKkfud fof/k gSa ftlds }kjk Complex Table Structure dks Simple Table Structure esa ifjofrZr fd;k tkrk gSaA
Table esa ls Redundancy dks de djus o Database Inconsistency dks gVkus ds fy;s dqN Rules dks Follow dj ukeZykbts’ku fd;k tkrk gSaA blesa ;g Hkh /;ku j[kk tkrk gSa fd Normalization ds le; Information dk dksbZ Loss uk gksA
Normalization ds cgqr ls ykHk gS] ftlds }kjk Fast Sorting, Indexing o Clustering dh tk ldrh gSa o ;g Table Structure dks Simple cukus dk dk;Z Hkh djrk gSaA fdlh Hkh Database Design dks vPNk cukus ds fy;s fuEu Rules dks Follow fd;k tkrk gSa%&
(1) gj Table esa ,d Identifier dk gksuk vko’;d gSaA
(2) gj Table esa Singal Type dh Entity dks Store fd;k tkuk pkfg;sA (3) Null Value dks de ls de Store fd;k tkuk pfg;sA
(4) Values dk Repetition ¼iqujko`fr½ Hkh de ls de gksuk pkfg;sA
Normalization Concept dks Apply djus ds fy;s vyx&2 Normal Forms dks mi;ksx esa fy;k tkrk gSaA Vscy ges’kk fdlh u fdlh Normal Form esa gksrh gSaA eq[;r% mi;ksx esa yh tkus okyh Normal Forms fuEu gS%&
(1) First Normal Form (1NF) (2) Second Normal Form (2NF) (3) Third Normal Form (3NF) (4) Fourth Normal Form (4NF)
(5) Boyce Coded Normal Form (BCNF) (6) Fifth Normal Form (5NF)
(1) First Normal Form (1NF):- fdlh Hkh Vscy dks 1NF esa rHkh dgk tk ldrk gSa tc Vscy dh gj Cell esa ,d Value gksA
Example:- ,d Relation Employee esa fuEu Attributes dks Insert fd;k x;k gSa%& Ecode:- (Ecode, Dept, Proj Code)
Employee
Ecode Dept Proj Code
E 101 Finance P27 P51 P20 E 303 Purchase P27 P22 E 709 Sales P51 P27
mijksDr Vscy esa lHkh Cell Value dks Insert ugha fd;k x;k gSa ijUrq Projcode Values ,d gh Cell esa ,d ls vf/kd gSaA vr% ;g Table Normalizaed Form eas ugha gSa] vr% bl ij 1NF ds Rule dks Apply fd;k tk,xk rFkk Table fuEu izdkj cusxh%&
Employee
Ecode Dept Proj Code
E 101 Finance P27 E 101 Finance P51 E 101 Finance P20 E 303 Purchase P27 E 303 Purchase P22 E 709 Sales P51 E 709 Sales P27
mijksDr Table 1NF esa gSaA
(2) Second Normal Form (2NF):- dksbZ Hkh Table 2NF esa rHkh gksxh tc og 1NF esa gks rFkk Row dk gj Attribute Primary Key in Functionally Dependent gksuk pkfg;s u fd Primary dh ds fdlh Part ijA
vr% fdlh Hkh Vscy dks 2NF esa cnyus ds fy;s fuEu fu;eksa dks Follow fd;k tkrk gSa%&
(1) mu Attributes dks Find dj mUgsa gVkuk tks Primary Key dks Part ¼Hkkx½ in dependent gksA mUgsa vyx Vscy esa Store djukA
(2) vU; cps Attributes dks ,d lkFk ,d Vscy esa j[kukA
Example:- Project Table esa fuEu Attributes dks 'kkfey fd;k x;k gSa%& Project:- (Ecode, Pcode, Dept, Hours}
PROJECT
Ecode Pcode Dept Hours
E1 P27 Finance 90 E2 P27 Pruchase 5 E3 P51 Sales 7 E1 P51 Finance 100 E1 P20 Finance 50 E3 P27 Sales 30
mijksDr Table 2NF esa ugha gSa ;k Table esa fuEu leL;k gSa%&
(1) fdlh Hkh Employee ds department dh rc rd Store ugha fd;k tk ldrk tc rd fd mls dksbZ Project u fn;k x;k gksA
(2) Code o Dept. ckj&2 Repeat gks jgs gSa vr% Information Updation esa Hkh Problems vk,xhA ftlls Inconsistency c<+sxhA
(3) ;fn dksbZ Employee Project Complete dj ysrk gSa rks Employee dk Record ;k Project Delete djus in iwjk Record Delete gks tk,xkA
mijksDr Table Non Key Attribute ¼tks Primary Key esa 'kkfey ugha gSa½ iwjh Primary Key (Key Attribute) in Functionally Depend gksus pkfg;sA
(1) lcls igys Dept. (Non-Key Attribute) dh dependency dks pSd fd;k tk,xkA Ecode ds fy;s Dept dh Value ,d ges’kk ,d gS vr% Dept, Ecode in Functionally Dependent gSaA ijUrq Proj Code ds fy;s Dept. dh Value ,d ls vf/kd gSa vr% Dept Pcode in Functionally dependent ugha gSaA
vr% Ecode+Pcode dks 'kkfey (Whole Key) djus in Hkh Dept Functionally Dependent ugha gSa vr% dept Ecode in rks Functionally dependent gSa ijUrq Pcode in ugha vr% Part of the Primary Key ij Dept ij ughaA
(2) Hours (Non-Key Attribute) dh dependency dks Check djuk gSaA Ecode ds fy;s Hours dh ,d ls T;knk Value gS vr% Hours, Ecode in Functonally Dependent ugha gSaA gj Project ds fy;s ;k Pcode ds fy;s Hkh Hours dh ,d ls vf/kd Values gSa vr% Hours, Pcode ij Hkh Functionally Dependent ugha gSaA ijUrq tc iw.kZr% Primary Key dh ckr dh tkrh gSa rks Hours (Pcode+Ecode) in Functionally dependent gSaA
vr% Dept ,d ,slk Non-Key Attribute gSa tks Relation dh Primary Key in Functionally Dependent ugha gSaA vr% ml Non Key o Key Attribute ftl ij Depend djrh gSa nksuks dks Table ls vyx dj fn;k tk,xkA
(1) Dept = {Ecode, Dept}
(2) Project = {Ecode, Pcode, Hours}
(3) Third Normal Form (3NF):- dksbZ Hkh Relation 3NF esa rHkh dgykrk gSa t cog Realtion 2NF esa gks rFkk gj Non-Key Attribute flQZ vkSj flQZ Primary Key ij dependent gksA
vr% fdlh Hkh Table dks 3NF esa cnyus ds fy;s fuEu Rules dks Follow fd;k tkrk gS%&
(1) mu Non Key Attributes dks <w¡<dj Rename djuk tks Primary Key ds vykok ,d nwljs ij Hkh depend djrk gksA
(2) mu lHkh Attributes dks ,df=r djukA
Example:- ,d Relation Employee esa fuEu Attributes dks 'kkfey fd;k x;k gSa%& Employee = {Ecode, Dept, Dept Head}
EMPLOYEE
Ecode Dept Dept Head
E1 Sales E705
E2 Pruchase E302
E3 Purchase E302
E4 Sales E705
E5 Finance E301
mijksDr Relation esa lHkh izdkj dh Anomalies (Problems) mifLFkr gS%& (1) Updation
(2) Deletion
vr% Table dks 3NF ds fy;s pSd djuk gksxkA bl Vscy ds fy;s Primary Key – Ecode gSaA
(1) gj Ecode dh Value ds fy;s Dept dh ,d Value gSa vr% Dept, Ecode in Functionally dependent gSaA (2) blh izdkj gj Ecode ds fy;s DeptHead Hkh ,d nwljs in Functionally Dependent gSaA vr% bu nksuks
Attributes dks vyx Table esa decompose dj fn;k tk,xkA vr% ,d Relation nks Parts esa divide gks tk,xk%&
(1) Employee = {Ecode, Dept} (2) Department = {Dept, Deptifead}
(4) BOYCE-Codd Normal form (BCNF):- dHkh&dHkh 3NF dh ifjHkk"k dqN Tables ds fy;s mi;qDr ugha gksrh tSls%&
(1) tc Vscy esa ,d ls vf/kd Candidate Keys gksA (2) tc Multiple Candidate Keys Composite gksA
(3) tc Multiple Candidate Key esa ,d Key Attribute Common gksA
bu lHkh dkj.kksa ls ubZ Normal Form develop dh xbZ ftls BCNF dgk tkrk gSaA PROJECT
Ecode Name Pcode Hours
E1 A P2 48 E2 B P5 100 E3 C P6 15 E4 D P2 250 E4 D P5 75 E1 A P5 40
bl Table ds fy;s Primary Key Ecode Pcode gSa ijUrq name o Pcode dks Hkh Primary Key pquk tk ldrk gSa] vr% ;g Candidate Key gSaA
mijksDr Table esa fuEu lwpuk,¡ izkIr gksrh gSa%& (1) Table esa Multiple Candidate Key gS%&
(1) Ecode + Pcode (2) Name + Pcode
(1) Candidate Keys Composite gSaA
(2) lHkh Condidate Keys esa Pcode ,d ,slk Attribute gSa tks Common gSaA
vr% bl Condition esa BCNF dks Apply fd;k tkuk pkfg;s ijUrq lkFk Functional deptendency dks Hkh check fd;k tkrk gSa%&
(1) Hours Primary Key in Functionally Dependent gSaA (2) Hours, Name + Pcode ij Hkh Functionally dependent gSaA (3) Name, Ecode ij Hkh Functionally Dependent gSaA
(4) Ecode Hkh Name ij Functionally Dependent gSaA vr% BCNF ds fy;s fuEu Rules dks Follow fd;k tk,xk%&
(1) Overlapped Condidate Key dks <w¡<dj mls Remove djuk o og ftl in dependent gSa mlds lkFk vyx Table eas decompose djukA
(2) vU; Attributes dks ,d lkFk ,d Table esa j[kukA vr% Name o Ecode dks vyx Table esa j[kk tk,xk%& (1) Employee:- Ecode Name
(2) Project:- Ecode Pcode Hours
(4) Fourth Normal Form (4NF):- lHkh Normal Form (BCNF) rd Apply djus ij Hkh Relation esa tks Main Problem jg tkrh gSa og gSa Information dk Repeat gksukA
tc ,d gh Attribute ds fy;s fdlh nwljs Attribute dh ,d ls vf/kd Values gks rks bl izdkj dh leL;k dks nwj djus ds fy;s Multivalued dependency dks Apply fd;k4 tkrk gSaA ftl Normal Form esa Multivalue dependency dks Consider fd;k tkrk gSa mls 4NF dgk tkrk gSaA
5NF (PJNF):- tc Relation esa Join dependency dks Consider fd;k tkrk gSa rks bl izdkj dh Normal Form Project Join Normal Form ;k Fiften Normal Form dgykrh gSaA
UNIT-IV
INDEXING & HASHING
fdlh Book ;k Card Catalog dh rjg gh Database ds Indexes dks Maintain fd;k tkrk gSaA mnk% ;fn Account Number ds vk/kkj ij Account Table ls Record Add djuk gks rks Database System] Index esa ls Disk Block <¡w<dj Record dks Main Memory esa ykrk gSaA
;fn Index Hkh Sorted gks rks Record dks <w¡<us esa le; de yxrk gSaA eq[;r% nks izdkj Index dks mi;ksx esa fy;k tkrk gSa%&
(1) Ordered Index:- ;g Database dh Sorted Values ij fuHkZj djrh gSaA
(2) Hash Index:- blesa Values dks Bucket esa Uniformly Store fd;k tkrk gSaA Bucket esa fdlh Value dks Store fd;k tkrk gSa blds fy;s ,d Function dks mi;ksx esa fy;k tkrk gSa ftls Hash Function dgk tkrk gSaA nksuks izdkj dh Indexing ds fy;s cgqr lh fof/k;k¡ viukbZ xbZ gSa] ijUrq dksbZ Hkh rduhd mi;qDr ugha gSaA gj Technique dks eq[;r% fuEu Factors ds }kjk ekik tkrk gSa%&
(1) Access Types:- blesa Records dks fdlh Attribute ls Find fd;k tkrk gSa rFkk lkFk mu Records dks Hkh Find fd;k tk ldrk gSa tks Specific Range esa vkrk gksA
(2) Access Time:- fdlh MkVk vkbVe ;k Set on item dks <w¡<us esa yxk le;A
(3) Insertion Time:- fdlh u;s Date Item dks Database esa Insert djus esa yxk le;A (4) Deletion Time:- fdlh MkVk vkbVe dks Database ls Delete djus esa yxk le;A (5) Space Overhead:- Index Structure ds }kjk vfrfjDr mi;ksx esa fy;k x;k LislA
og Attribute ftlds }kjk fdlh QkbZy ds Record dks Search fd;k tkrk gSa] Search Key dgykrh gSaA
Ordered Indexes:- Records dh Fast Searching ds fy;s Index Structure dks mi;ksx esa fy;k tkrk gSaA fdlh Book ds Index dh rjg gh Ordered Index esa Hkh Search Key Values dks Sorted Order esa ifjHkkf"kr fd;k tkrk gSaA bl izdkj gh QkbZy dks vyx&2 Search Key ds vk/kkj ij Index fd;k tk ldrk gSaA ;fn fdlh QkbZy esa Records dks Sequentially j[kk x;k gSa rks Primary Index esa Search Key Values dks Hkh Sequentially Define fd;k tk,xkA Primary Index dks Clustering Index Hkh dgk tkrk gSaA Primary Index esa eq[;r% Search Key Primary Key gh gksrh gSaA ijUrq ,slk vko’;d ugha gSaA Sequential Order ds vykok ;fn fdlh vU; order dks use esa ysdj Search Key dks define fd;k x;k gSa] rks ;g Index Secondary Index dgykrk gSaA
(1) Primary Index:- lHkh Files dks fdlh Search Key ds vk/kkj ij Sequentially Ordered fd;k tkrk gSaA os Files ftlesa Search Key Primary Index ds Concept ij dk;Z djrh gSa mUgsa Index Sequential File dgk tkrk gSaA
A-No. BRANCH Amount
A-217 DELHI 750 A-101 DELHI 500 A-110 DELHI 600 A-215 HYDERABAD 700 A-102 HYDERABAD 400 A-201 HYDERABAD 900 A-218 MUMBAI 700 A-222 MUMBAI 700 A-305 MUMBAI 350 SEQUENTIAL FILE
DENSE AND SPARSE INDEX:- Ordered Index dks eq[;r% nks Hkkxksa esa ck¡Vk x;k gS%& (1) DENSE INDEX
(2) SPARSE INDEX DELHI
HYDERABAD
(1) DENSE INDEX:- tc QkbZy dh gj Search Key Value ds fy;s Index Record Maintain fd;s tkrs gSa rks bl izdkj ds Index dks dense Index dgk tkrk gSaA Sparse Index dh vis{kk dense Index ls Fast Searching Perform dh tk ldrh gSaA Index Record esa Search Key Value rFkk Search Key ds First Data Record ds Pointer dks j[kk tkrk gSaA
A-No. BRANCH Amount
A-217 BIKANER 750 A-101 BIKANER 500 A-110 BIKANER 600 A-215 CALCUTTA 200 A-102 CALCUTTA 400 A-201 DELHI 250 A-218 MADRAS 400 DENSE INDEX
(2) Sparse Index:- ;s Index-Record dqN Serach Key Values dks gh Store djrk gSaA bl izdkj ds Index ls Record dks Search djus ds fy;s Index Table ls dh mlls cM+h ;k NksVh Value dks Search dj Sequentially Records dks Search fd;k tkrk gSaA
Sparse Index dh vis{kk Dense Index ls fast searching perform dh tkrh gSA
A-No. BRANCH Amount
A-217 BIKANER 750 A-101 CALCUTTA 500 A-110 CALCUTTA 600 A-215 MADRAS 700 A-102 PILANI 400 A-201 PILANI 900 A-218 PILANI 700 A-222 RURKI 100 A-350 RURKI 350 SPARSE INDEX
MULTILEVEL INDICES:- ;fn Sparse Index dks mi;ksx esa ysrs gSa rks Records ij Processing ds fy;s Index Hkh cgqr cM+k gks tkrk gSaA tSls ;fn QkbZy esa 10,00,00 Records gSa rFkk gj Block esa 10 Records dks Store fd;k x;k gSa o ;fn gj Block ds fy;s ,d Index Record cuk;k x;k gS rks Hkh Index esa 10,000 Records dks LVksj djuk iM+sxkA Index Records Data Records ls NksVs gksrs gSa vr% ;g eku ysrs gSa fd ,d Block esa 100 Records dks j[kk x;k gSaA vr% Index dks 100 blocks dh vko’;drk gksxh rFkk bu Indexes dks Disk ij Sequential File ds :i esa Store fd;k tkrk gSaA
;fn Index dh lkbZt NksVh gks o mls Main Memory esa j[kk tk, rks Indexing }kjk Records Searchdjus esa de le; yxsxkA o ;fn Index cM+k gS rks mls Disk ij j[kk tk,xk ftlls Disk Block Read djus esa le; vf/kd yxsxkA vr% blds fy;s Binary Search dks mi;ksx esa fy;k tkrk gSaA
vr% bl leL;k dks nwj djus ds fy;s Primary Index ij iqu% Sparse Index cuk;k tkrk gSaA ftlls File ij nks Index Create gksrs gSa%& (1) Inner Index (2) Outer Index BIKANER CALCUTTA DELHI MADRAS BIKANER MADRAS RURKI
bl izdkj tc Indexing ds fy;s nks levels dks Create fd;k tkrk gSa o muesa ls fdlh vko’;d Block dks gh Read fd;k tkrk gSa] rks bl izdkj dh Indexing dks Two-level Indexing dgrs gSaA blesa Outer Index dks Main Memory esa j[kk tkrk gSaA ;fn Outer Index cM+k gks rks mldh iqu% Indexing dj nh tkrh gSa o lcls var esa cus Index dks Main Memory esa j[kk tkrk gSaA bl izdkj dh Indexing dks Multi-lelvel Indexing dgk tkrk gSaA
SECONDARY INDEX
tc Multilevel Index dks mi;ksx esa fy;k tkrk gSa rks, Index level dks fuEu izdkj ifjHkkf"kr fd;k tkrk gSaA (1) Inner Index (Primary Index)
(2) Outer Index (Secondary Index)
Secondary Index ges’kk Dense gksuk pkfg;sA ftlesa gj Search Key Value dh Index Entry dks j[kk tkrk gSa o lkFk lkFk gj Record Pointer dks Hkh j[kk tkrk gSaA Primary Index Sparse Index gks ldrk gSa ftlesa dqN Search Key Values dks gh LVksj fd;k tkrk gSaA
Secondary Index ds }kjk Query Performance dks lq/kkjk tkrk gSa] ftlesa Primary Index dh Search Key Values dks mi;ksx esa fy;k tkrk gSaA
A-No. BRANCH Amount
A-101 DELHI 500 A-217 BOMBAY 750 A-110 DELHI 600 A-215 MADRAS 700 A-102 PILANI 400 A-201 PILANI 900 A-218 RURKI 700 A-222 RAJKOT 700 SECONDARY INDEX
B+ TREE INDEX FILES:- Index Sequetial file Organization dh eq[; gkuh ;g gSa fd tSls&2 File esa Records c<+rs gSa oSls&2 bl File Organization dk Performance level de gksrk tkrk gSaA
vr% blds fy;s B+ Tree Index Structure dks mi;ksx esa fy;k tkrk gSa] ftlls QkbZy esa Records dk Insertion o deletion vklkuh ls fd;k tk ldrk gSaA B+ Tree Index ,d Balanced Tree dh Form esa jgrk gSa ftlesa Root ls Leaf rd gj Path dh yEckbZ lkeku gksrh gSaA
Data Block 0 Data Block 1 2 (Inner Index) On Disk (Outer Index) Main Memory
B+ Tree Structure Insertion o deletion mifjO;; dks rks Remove dj nsrk gSa ijUrq Space Overhead dks Add dj nsrk gSa ijUrq ;g mifjO;; vU; mifjO;;ksa ls vf/kd mi;qDr gSaA D;ksafd blls File Organization dk Performance Level c<+ tkrk gSaA B+ Tree Structure dks Index ds lkFk lkFk File Record ds Organizer ds :i esa mi;ksx esa fy;k tkrk gSaA blesa B+ tree ds leaf Nodes esa Pointers ds LFkku ij Record dks Store fd;k tkrk gSaA
B+ Tree File Organization
B+ Tree esa leaf node esa nonleaf Node ds Point ls] ,d de Records dks j[kk tkrk gSaA B+ Tree Index o B+ Tree File Organization nksuksa esa Insertion o deletion ,d gh izdkj ls fd;k tkrk gSaA ;fn fdlh B+ Tree dks ifjHkkf"kr fd;k tk, rks fuEu ckrksa dks /;ku esa j[kuk vko’;d gSa%&
(1) ;fn n dh Value nh xbZ gS rks mlesa N-1 Value o N Pointers dks j[kk tk,xk tSls%&
;fn N=3 gks o Search Key Branch Name gSa rks ,d Node esa N-1 Values rFkk N= 3 Pointers dks Store fd;k tk,xkA
B-Tree Index Files:- B-Tree Index fcYdqy B+ Tree Index dh rjg gh gksrh gSaA nksuksa Index Files esa eq[; vUrj ;g gSa fd B-Tree Index esa Search Key Values dh Redundaut (Duplicate) Values dks Remove ¼nwj½ dj fn;k tkrk gSaA
B Tree ds }kjk Search Key Values dks ,d ckj gh iznf’kZr fd;k tkrk gSaA leaf node fcYdqy B+Trees dh rjg gksrh
I C F K M A,4 B,8 C1 D5 E4 F7 G3 H3 I4 IB K1 L6 M4 H8 P6 Val1 Val 2
1 Pointer 2nd Pointer 3rd Pointer
Bombay y Delhi z
A-212 Bombay A-101 Delhi A-110 Delhi
Static Hashing:- Sequential File Organization dh ,d deh ;g gSa fd MkVk dks Search djus ds fy;s Index Structure dks Access fd;k tkrk gSa o blds fy;s Binary Search dks mi;ksx esa fy;k tkrk gSaA ftlls vf/kd Input/Output Operations dks Perform djuk iM+rk gSaA
ijUrq tc File Organization, Hashing rduhd in fuHkZj djrh gSa rks blls vf/kd I/O Operation dh vko’;drk ugha gksrhA Hashing ds }kjk Hkh Index dks cuk;k tkrk gSaA
Hash File Organization:- bl Organization esa Record dh Search Key Value ij ,d Function ¼QaD’ku½ Perform fd;k tkrk gSaA ftlls vko’;d Disk Block ds vko’;d Record dks vklkuh ls Search dj fy;k tkrk gSaA Hashing ds vUrxZr Bucket Keyword dks mi;ksx esa fy;k tkrk gSaA ftlesa ,d ;k ,d ls vf/kd Records dks Store dj j[kk tkrk gSaA vr% Bucket ,d Disk block tSlk gSaA ysfdu ;g ,d Disk Block ls NksVk ;k cM+k gks ldrk gSaA
ekuk K ds }kjk lHkh Search Key Values dks iznf’kZr fd;k tkrk gSa rFkk B }kjk lHkh Bucket Address dks iznf’kZr djrk gSaA Hash Function h ,d Function gSa ftlds }kjk K Search Key Values ls B Bucket ds Specific Record ij igq¡pk tkrk gSaA
fdlh Record dks mldh Search Key (k1) ds lkFk Store djus ds fy, ml ij h (Hash Function) (ki) ijQkeZ fd;k tkrk gSaA tks Record ds Bucket Address dks Return djrk gSaA
bl izdkj Records dks mijksDr fof/k }kjk Delete Hkh fd;k tk ldrk gSaA
Hash Function:- lcls csdkj Hash Function og gSa ftlesa ,d gh Bucket esa lHkh Search Key Value dks j[kk tkrk gSaA ftlls fdlh Hkh Record dks <¡<us ds fy;s iwjh Bucket Record dks Search djuk iM+rk gksA
,d vPNk Hash Function ogh gSa ftlesa Key Values dks lHkh Bucket ,d :i esa Store fd;k tk,A vFkkZr~ lHkh Buckets esa ,d leku Records dks Store fd;k tk,A vr% gj Bucket esa Records dh ek=k leku gksrh gSaA
vr% Design time ij User ugha tkurk fd fdl Search Key Values dks File esa dgk¡ LVksj fd;k x;k gSaA vr% Search Key Values dks Bucket esa j[kus ds fy;s Hash Function dks mi;ksx fd;k tkrk gSaA Buckets esa Search key Values dk distribution (forj.k) fuEu izdkj fd;k tkrk gSa%&
(1) forj.k Uniform gksuk pkfg, ¼leku½ (2) forj.k Random ¼vleku½ Hkh gks ldrk gSaA
Bucket Overflow:- tc Record dks Insert fd;k tkrk gSa rks Bucket esa ml Record ds fy;s Space Hkh dh tkrh gSaA ijUrq ;fn Bucket esa vko’;d Space ugha gS] rks Bucket Overflow dh ifjfLFkfr mRiUu gksrh gSaA Bucket Overflow cgqr ls dkj.kksa ls mRiUu gksrk gSa tks fuEu gSa%&
(1) Insufficient Buckets:- ¼tc iw.kZ :i ls Buckets miyC/k uk gks½%& Buckets (nB) ges’kk nr/fr ls vf/kd gksuh pkfg;sA ;gk¡ nr- lHkh Records ftUgsa Store djuk gksA fr- ,d Bucket esa fit gksus okys Records dh la[;k vr% nB tc nr/fr ls vf/kd gksxk rHkh Bucket Overflow dh leL;k dks gVk;k tk ldrk gSaA
(2) Skew ¼Ld;w½%& dqN Buckets esa vU; Bucket dh vis{kk T;knk Records dks Store dj fn;k tkrk gSa tcfd nwljh Buckets esa Space cpk gksrk gSaA bl izdkj dh Condition dks Skew dgk tkrk gSaA Skew eq[;r% nks dkj.kksa ls mRiUu gksrh gSa%&
¼1½ tc cgqr ls Records dh ,d Search dh gksA
¼2½ tc Hash Function }kjk Search Keys dk vleku forj.k fd;k tk,A
Overflow dks jksdus ds fy;s ;g vko’;d gSa fd vU; Buckets dks Allocate dj fn;k tk, Bucket Overflow dks Overflow Bucket }kjk Hkh nwj fd;k tk ldrk gSaA tSls%& ;fn Record dks Bucket b esa Store djuk gSa o b igys ls iwjh gks pqdh gSa rks System }kjk b dks Oveflow Bucket ns nh tkrh gSa rFkk Record dks Overflow Bucket esa Insert dj fn;k tkrk gSaA ;fn Overflow Bucket Hkh Full gks tk, rks System }kjk vU; Overflow Bucket Provide djok nh tkrh gSaA bl izdkj ;g Øe pyrk jgrk gSaA lHkh Overflow Buckets dks ml Bucket ds lkFk Link list dh rjg Store dj fn;k tkrk gSaA bl izdkj dh List dks Overflow Chaining dgk tkrk gSaA
HASH INDICES:- Hasing dks File Organization ds lkFk&lkFk Index-Structure ds fy;s Hkh mi;ksx esa fy;k tk ldrk gSaA hash index ds }kjk Search Key dks mlds Pointer ds lkFk Hash File Structure esa Store fd;k tkrk gSaA Dynamic Hashing:- tc Bucket b esa Fix Address dks j[kk tkrk gSaA Static Hashing ds le; dHkh dHkh Serious Problems Occur gks tkrh gSaA vr% bl izdkj dh Condition Occur uk gks blds fy;s fuEu Option dks mi;ksx esa fy;k tkrk gSa%&
(1) Current File Size ds vk?kkj ij Hash Function dks pquuk
(2) ml Hash Function dks pquuk tks Current File ds lkFk lkFk vfrfjDr Space dks Hkh Consider djs ftlls Performance Hkh c<rh gSa ijUrq Space vf/kd Waste gksrk gSaA
(3) File Growth ¼c<us½ ds lkFk lkFk Hash Structure dks Hkh iqu% Reorganize djuk ;g Operation time Consuming rks gSaA ijUrq Accessing ds fy;s vko’;d Hkh gSaA
Dynamic Hashing fof/k;ksa ds }kjk Hash Function dks Database ds c<us ;k de gksus ds lkFk&2 ifjofrZr fd;k tk ldrk gSaA vFkkZr~ Hash Function Database dh Growth dks rks ugha cny ldrk ijUrq Growth ds lkFk lkFk Hash Function dks ifjofrZr fd;k tk ldrk gSaA
INDEX DEFINITION IN SQL:- Index Database dh Efficient Processing ds fy;s vko’;d gksrs gSa ftlesa Transaction dks Update fd;k tkrk gSaA o mu ij Queries Hkh Perform dh tkrh gSaA SQL esa Index Create djus ds fy;s Create Index Command dks mi;ksx esa fy;k tkrk gSaA
Syntax:- Create index <index_name> on
<relation_name> (<attributes>) Attributes esa mu Columns dks 'kkfey fd;k tkrk gSa ftu ij Index Create djuk gksA
Bucket 0
Bucket 1
Bucket 2
UNIT-V
FALIURE CLASSIFICATION:- (System esa gksus okys Faliure ds Hkkx):- System esa dbZ izdkj ds Faliures gksrs gSaA ijUrq lcls Simple Faliure og gSa ftlls fdlh Hkh izdkj dk Information dk Loss uk gksA ijUrq ftuesa Information Loss gksrk gSaA mlls cgqr eqf’dy ls Recovery dh tkrh gSaA eq[;r% mRiUu gksus okys Faliures fuEu gSa%& (1) Transaction Faliure:- fdlh Hkh Transaction ds Fail gksus dk dkj.k eq[; nks Errors gks ldrh gSa%&
(1) Logical Error:- tc Transaction dk Execution vf/kd le; rd fdlh Internal ¼vkarfjd½ Condition ds dkj.k Normal u jg ik, rks ;g Logical Error dgykrh gSaA tSls%& Data dk uk feyuk , Data dk Oveflow gksuk vkfnA
(2) System Error:- tc System fdlh vupkgh fLFkfr tSls dead lock dh fLFkfr esa vk tk, o blls Transaction Normal Execution esa u jgs rks bl izdkj dh Error dks System Error dgk tkrk gSaA
(2) System Crash:- tc Hardware, Database Software ;k Operating System esa Error vk tk, ftlls Volatile Storage dh Information lqjf{kr uk jgs rks blls Hkh Transaction :d tkrh gSaA
(3) Disk Faliure:- Head ds Crash gksus ;k Disk Block ds [kks tkus ls Data Transfer Operation ds lkFk tks Faliure mRiUu gksrk gSa mls Disk Faliure dgk tkrk gSaA
vr% MkVkcsl esa Consistency cuk, j[kus o Failure ls Recovery ds dqN Techniques ¼fof/k;k¡½ viukbZ xbZ gSa] ftUgsa Recovery Alogrithm dgk tkrk gSaA ;s eq[;r% nks izdkj ds gksrs gS%&
(1) Normal Transaction Processing ds fy;s mi;qDr Iformation dk gksuk rkfd Recovery vklkuh ls gks ldsA (2) Faliure dks Recover djrs le; Database dks Consistent o Atomic cuk, j[krs gSaA
STORAGE STRUCTURE
Storage Media dks mldh Speed {kerk ds vk/kkj in ifjHkkf"kr fd;k tkrk gSaA vr% eq[;r% Storgae nks izdkj ds gksrs gSa%& (1) Volatile Storage
(2) Non-Volatile Storage
(1) Volatile Storage:- System Crash ds nkSjku Volatile Storage esa j[kh xbZ Information ugha gVrh gSaA Main Memory ;k Cache Memory bl Storge ds eq[; mnkgj.k gSaA Volatile Storage ls MkVk dks Fastly Access fd;k tkrk gSaA
(2) Non-Volatile Storage:- System Crash dk Non-Volatile Storage ij vf/kd izHkko iM+rk gSaA Non-Volatile Storage, Volatile Storage dh vis{kk Slow gksrs gSa D;ksafd Disk ;k Tape (Non-Volatile Storage) Electro Mechanical ¼bysDVªkseSdsfudy½ gSa tcfd Volatile Storage Chips ds cus gksrs gSaA
Stable Storage:- Stable Storage esa j[kh xbZ Information dk Loss ugha gksrk gSaA TRANSACTION MODEL
Transaction izksxzke Execution dh ,d ;wfuV gSa ftlds }kjk fofHkUu Data Items dks Access o Update fd;k tk ldrk gSaA User }kjk Execute dh tkus okyh lHkh Transactions ;k Statements dks Begin Transactoin o End Transaction ds chp j[kk tkrk gSaA vr% Database System esa fdlh Hkh Transaction dh Properties dks Follow fd;k tkuk vko’;d gSa%&
(1) Atomicity ¼,VkWfeflVh½:- Transaction esa gksus okys lHkh Operations, Database esa lkQ&2 iznf’kZr gksus vko’;d gSaA
(2) Consistency:- tc Database esa dksbZ ,d Transaction Execute gks jgk gks rks nwljk Transaction Execute ugha gksuk pkfg;s] ftlls Database esa Consistency cuh jgrh gSaA
(3) Isolation:- tc Database esa Multiple Transaction Execute gks jgh gks rks igyh Transaction ds [kRe gksus ij gh nwljh Transaction dks Execute gksuk pkfg;sA
(4) Durability:- tc ,d Transaction iwjh Execute gks tk, rHkh mlls lacaf/kr Updates dks Database esa fd;k tkuk pkfg;sA
