Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Primary index
A primary index is a file that has a sorted series of records having two columns: a block address for that key field in the data file; and the ordering key field. The ordering key field for this primary index can be the primary key of the data file. Primary index have one index entry for every value of the ordering key field. An entry in primary index file has the index value of the pointer to that data block and a first record of the data block.
Let us talk about primary index with the help of an instance. Let us suppose a student database as (Supposing that one block keeps only four student records.):
Enrolment Progra- Number Name City mme
BLOCK 1
2109348
ANU VERMA
CHENNAI
CIC
2109349
ABHISHEK KUMAR
CALCUTTA
MCA
2109351
VIMAL KISHOR
KOCHI
BCA
2109352
RANJEETA JULIE
BLOCK 2
2109353
MISS RAJIYA BANU
VARANASI
MBA
2238389
JITENDAR KASWAN
NEW DELHI
2238390
RITURAJ BHATI
2238411
AMIT KUMAR JAIN
BLOCK 3
2238412
PAWAN TIWARI
AJMER
2238414
SUPRIYA SWAMI
2238422
KAMLESH KUMAR
MUMBAI
BSC
2258014
DAVEN SINGHAL
BLOCK 4
2258015
S SRIVASTAVA
2258017
SHWETA SINGH
2258018
ASHISH TIWARI
2258019
SEEMA RANI
LUCKNOW
...
BLOCK r
2258616
NIDHI
2258617
JAGMEET SINGH
2258618
PRADEEP KUMAR
2318935
RAMADHAR
FARIDABAD
BLOCK N-1
2401407
BRIJMISHRA
BAREILLY
2401408
AMIT KUMAR
2401409
MD. IMRAN SAIFI
AURANGABAD
2401623
ARUN KUMAR
BLOCK N
2401666
ABHISHEK RAJPUT
2409216
TANNUJ SETHI
2409217
SANTOSH KUMAR
ALMORA
2409422
SAKSHI GINOTRA
Figure: A Student file stored in the order of student enrolment numbers
Attributes having a one value for a particular entity. For instance, Age is a single valued attribute of a student entity. Attributes that have more than single values
What are the uses of functional dependencies? To test relations to see whether they are legal under a given set of functional dependencies. To state constraints on the set
UNION If R1 and R2 are two union compatible relations then R3 = R1 ∪ R2 is the relation having tuples that are either in R1 or in R2 or in both. In case, R3 will have tuples
Is it mandatory to declare all the tables in Report by the key word tables for all the tables that exist in the structure of LDB, and are being explained in the Database part of LD
Ask question #MinimRead Dennis et al. Chapter 6: Minicase 2. Work through it and answer the questions. See the attached example. SequenceDiagram.png Based on the structural mod
Explain controlled redundancy? Controlled redundancy : The replication of data within the data warehouse for the purposes of improved data access or understand ability.
Deadlock And Its Prevention: As seen earlier, though two phase locking protocol handles the trouble of serialisability, but it causes some troubles also. For instance, consider th
Company Database: a-)Here is the ER Model b-)Here is the Relational Model: IMPORTANT NOTICE FOR SOLUTION TYPE: ***THIS ASSIGNMENT WILL BE SOLVED BY THE
What is D command work in the respect of QBE? D: It is the command inside QBE to delete tuple(s) from the relation.
Describe the types of Inheritance 1. Single inheritance 2. Multiple inheritance 3. Hierarchical inheritance 4. Multilevel inheritance
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd