...power can be measured in two ways: on the linear scale, by the number of watts that are being transmitted; and on a relative scale, by the number of decibels (dBs) instead of watts. Decibel milliwatt (dBm) is the logarithmic power ratio (in dB) of the measured power in milliwatts referenced to one milliwatt (mW). Notice that the reference point is specified as 1 mW = 0 dBm. 3’s and 10’s rules are shortcuts for estimating the increase or decrease of these power levels. In this lab, students will practice basic RF calculations, including · converting from mW to dBm; · converting from dBm to mW; and · estimating power levels using the 3’s and 10’s rules. Task 1: Converting between dBm and mW Applying the 3’s and 10’s rules, the relationship between dBm and mW is estimated as shown in the following (partial) table. 3’s rule|10’s rule| ……|……| 0.125 mW = -9 dBm|0.001 mW = -30 dBm| 0.25 mW = -6 dBm|0.01 mW = -20 dBm| 0.5 mW = -3 dBm|0.1 mW = -10 dBm| 1 mW = 0 dBm|1 mW = 0 dBm| 2 mW = 3 dBm|10 mW = 10 dBm| 4 mW = 6 dBm|100 mW = 20 dBm| 8 mW = 9 dBm|1,000 mW = 30 dBm| ……|……| Notice that as the mW value increases or decreased by the factor of 10, the dBm value increases and decrease by adding or subtracting 10. As the mW value doubles or halves, the corresponding dBm value increases and decrease by adding or...
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...DBMS vs. RDBMS • Relationship among tables is maintained in a RDBMS whereas this not the case DBMS as it is used to manage the database. • DBMS accepts the ‘flat file’ data that means there is no relation among different data whereas RDBMS does not accepts this type of design. • DBMS is used for simpler business applications whereas RDBMS is used for more complex applications. • Although the foreign key concept is supported by both DBMS and RDBMS but its only RDBMS that enforces the rules. • RDBMS solution is required by large sets of data whereas small sets of data can be managed by DBMS. 1. What is database? A database is a collection of information that is organized. So that it can easily be accessed, managed, and updated. 2. What is DBMS? DBMS stands for Database Management System. It is a collection of programs that enables user to create and maintain a database. 3. What is a Database system? The database and DBMS software together is called as Database system. 4. What are the advantages of DBMS? I. Redundancy is controlled. II. Providing multiple user interfaces. III. Providing backup and recovery IV. Unauthorized access is restricted. V. Enforcing integrity constraints. 5. What is normalization? It is a process of analysing the given relation schemas based on their Functional Dependencies (FDs) and primary key to achieve the properties (1).Minimizing redundancy, (2). Minimizing insertion, deletion and update anomalies. 6. What...
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...Lovely Professional University Case study on student record keeping system Name Abhishek Bhatt Regd. No. 11109390 Roll No. A21 Section K1104 Submittked By Submitted to Abhishek Bhatt Vipin Kumar Case Study case study on student record keeping system Table Of Content 1) Introduction 2) What is DBMS ? 3) Features/Advantages of DBMS. 4)Disadvantages of DBMS 5)Advantages of student record keeping system 6)Note * Introduction : * DBMS : DBMS Stands for Data Base Management System. It consists of interrelated data and set of programs to access those data. * Data : Raw information is called data. * Database : Database is a collection of interrelated data, contain information about one particular enterprise. * Interrelated Data : It is a type of data which is related to each other. e.g. Student and subject, parents and child. * About My Topic : My topic is about case study on student record keeping system * Introduction to case student record keeping system Student Record Keeping System is a comprehensive solution for all of a school’s student management needs, like enrollment...
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...Examination Paper of Database Management Systems IIBM Institute of Business Management Examination Paper Subject Code- E1010 Database Management Systems Section A: Objective Type (20 marks) This section consists of Multiple Choice Questions / True & False. Answer all the questions. Each Question carries 1 mark. MM.100 Multiple Choices: 1. Structured Query Language (SQL) is the language for working with: a. DDBMS b. RDBMS c. Both (a) & (b) d. None of the above 2. Decomposition in database design means: a. Breaking one table into multiple tables b. Breaking two table into multiple tables c. Composing multiple tables into one table d. None of the above Locking helps: a. Hiding the database b. To solve concurrency problems c. Both (a) & (b) d. None of the above 3. 4. Database optimizer: a. Enhances the speed of query execution b. Minimizes the speed of query execution c. Is a program d. None of the above 5. Data is __________. a. Raw facts b. Processed information c. Both (a) & (b) d. None of the above 6. Mobile computing means: a. Ability to use computer while on still b. Ability to use computer while on move c. Calculation with the help of mobile d. None of the above 1 IIBM Institute of Business Management Examination Paper of Database Management Systems 7. Operation Data Store (ODS) provides: a. Situation sensitive decision support & operational reporting b. Time sensitive decision support & operational reporting c. Both (a) & (b) d. None of the above 8. Transaction...
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...include code for the metadata of each file - Each application program must have its own processing routines for reading, inserting, updating, and deleting data - Lack of coordination and central control - Non-standard file formats Problems with Data Redundancy - Waste of space to have duplicate data - Causes more maintenance headaches The biggest problem: - Data changes in one file could cause inconsistencies - Compromises in data integrity SOLUTION: The DATABASE Approach - Central repository of shared data - Data is managed by a controlling agent - Stored in a standardized, convenient form Database Management System - A software system that is used to create, maintain, and provide controlled access to user databases - DBMS manages data resources like an operating system manages hardware resources Advantages of the Database Approach - Program-data independence - Planned data redundancy - Improved data consistency - Improved data...
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... * Real-world entity − A modern DBMS is more realistic and uses real-world entities to design its architecture. It uses the behaviour and attributes too. For example, a school database may use students as an entity and their age as an attribute. * Less redundancy − DBMS follows the rules of normalization, which splits a relation when any of its attributes is having redundancy in values. * Consistency − There exist methods and techniques, which can detect attempt of leaving database in inconsistent state. A DBMS can provide greater consistency as compared to earlier forms of data storing applications like file-processing systems. * Query Language − DBMS is equipped with query language, which makes it more efficient to retrieve and manipulate data. * ACID Properties − DBMS follows the concepts of Atomicity, Consistency, Isolation, and Durability (normally shortened as ACID). These concepts are applied on transactions, which manipulate data in a database. ACID properties help the database stay healthy in multi-transactional environments and in case of failure. * Multiuser and Concurrent Access − DBMS supports multi-user environment and allows them to access and manipulate data in parallel. * Multiple views − DBMS offers multiple views for different users. A user who is in the Sales department will have a different view of database than a person working in the Production department. * Security − DBMS offers methods to impose constraints...
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...of the real world and is used for specific purposes by one or more groups of users. A DBMS is a generalized software package for implementing and maintaining a computerized database. The database and software together form a database system. We identified several characteristics that distinguish the database approach from traditional fileprocessing applications, and we discussed the main categories of database users, or the actors on the scene.We noted that in addition to database users, there are several categories of support personnel, or workers behind the scene, in a database environment. We presented a list of capabilities that should be provided by the DBMS software to the DBA, database designers, and end users to help them design, administer, and use a database. Then we gave a brief historical perspective on the evolution of database applications.We pointed out the marriage of database technology with information retrieval technology, which will play an important role due to the popularity of the Web. Finally, we discussed the overhead costs of using a DBMS and discussed some situations in which it may not be advantageous to use one. In this chapter we defined a database as a collection of related data, where data means recorded facts. A typical database represents some aspect of the real world and is used for specific purposes by one or more groups of users. A DBMS is a generalized software package for implementing and maintaining a computerized database...
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...______________________________________ ------------------------------------------------- Roll No. : ______________________________________ ------------------------------------------------- ------------------------------------------------- An Introduction to Database Management Systems A database is a collection of related files that are usually integrated, linked or cross-referenced to one another. The advantage of a database is that data and records contained in different files can be easily organized and retrieved using specialized database management software called a database management system (DBMS) or database manager. DBMS Fundamentals A database management system is a set of software programs that allows users to create, edit and update data in database files, and store and retrieve data from those database files. Data in a database can be added, deleted, changed, sorted or searched all using a DBMS. If you were an employee in a large organization, the information about you would likely be stored in different files that are linked together. One file about you would pertain to your skills and abilities, another file to your income tax status, another to your home and office address and telephone number, and another to your annual performance ratings. By cross-referencing these files, someone could change a person's address in one file and it would automatically be reflected in all the other files....
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...Section A: Multiple Choices: 1. Structured Query Language (SQL) is the language for working with b. RDBMS 2. Decomposition in database design means a. Breaking one table into multiple tables 3. Locking helps b. To solve concurrency problems 4. Database optimizer b. Minimizes the speed of query execution 5. Data is __________. a. Raw facts 6. Mobile computing means d. None of the above 7. Operation Data Store (ODS) provides c. Both (a) & (b) 8. Transaction is c. Logical unit of work 9. Transitive dependency is a. Indirect dependency relationship 10. Row in RDBMS is called b. Tuple True & False: 1. Database keys do not allow identification of records. False 2. A key is a minimal set of key minimal. True 3. Joins cannot be used to retrieve data from multiple tables. False 4. Data redundancy prefers to duplication of data. True 5. DML is used to retrieve or manipulate data stored in a database. True 6. Database keys do not allow identification of records. Flase 7. A super key is a set of column that identifies every row in a table. True 8. System recovery is sub-classified into transaction recovery and media recovery. False 9. Media recovery deals with disk error. True 10. The task of a DDBMS is quite complex. False Section B: Short Questions (20 marks) 1. What is SQL? Why is it a powerful language? ANS: SQL is an acronym that stands for "Structured Query Language" and it's used primarily...
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...(Tribhuvan University) A STUDY IN THE ATTENDANCE MANAGEMENT SYSTEM OF HIMALAYAN WHITEHOUSE INTERNATIONAL COLLEGE Project Report on Database Management System In partial fulfillment of the requirements For the Bachelor’s Degree in Business Administration By: September 2014 Table of Contents Chapter I 1 INTRODUCTION 1 1.1 Introduction of the Organization 1 1.2 Attendance Management System 1 1.3 Overview 2 1.4 Economically Feasibility 2 1.5 Technical Feasibility 2 1.6 Behavioural Feasibility 2 Chapter II 3 LITERATURE SURVEY 3 2.1 Drawbacks Of Present System 3 2.2 Proposed System 3 2.2.1 Objectives of the Proposed System 3 2.2.2 Advantages of Proposed System 4 2.3 Scope 4 Chapter III 5 SYSTEM DESIGN 5 3.1 E-R-D Representations 5 3.2 E-R Diagram 6 3.3 Schema 7 3.4 Tabular Representation Of Schema 7 Chapter IV 10 IMPLEMENTATION 10 4.1 Syntaxes 10 4.2 Snapshots 11 Chapter V 14 CONCLUSION 14 BIBLIOGRAPHY 15 REFERENCES 16 LIST OF TABLES |Table no. |Title |Page no. | |3.4.1 |Tabular representation of Schema: Teacher |9 | |3.4.2 |Tabular representation of Schema: Teaches |9 | |3.4.3 |Tabular representation of Schema: Subject |9 ...
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...Notes on DBMS Internals Neil Conway neilc@samurai.com November 10, 2003 Preamble These notes were originally written for my own use while taking CISC-432, a course in DBMS design and implementation at Queen’s University. The textbook used by that class is Database Management Systems, 3rd Edition by Raghu Ramakrishnan and Johannes Gehkre; some of the material below may be specific to that text. This document is provided in the hope that it is useful, but I can’t provide any assurance that any information it contains is in any way accurate or complete. Corrections or additions are welcome. Distribution Terms: This document is released into the public domain. Query Evaluation External Sorting • A DBMS frequently needs to sort data (e.g. for a merge-join, ORDER BY, GROUP BY, etc.) that exceeds the amount of main memory available. In order to do this, an external sort algorithm is used. • 2-Way External Merge Sort: – In the first pass, each page of the input relation is read into memory, sorted, and written out to disk. This creates N runs of 1 page each. – In each successive pass, each run is read into memory and merged with another run, then written out to disk. Since the number of runs is halved with every pass, this requires log2 N passes. Since an additional initial pass is required and each pass requires 2N I/Os, the total cost is: 2N( log2 N + 1) – Thus, we can see that the number of passes we need to make is critical to the overall performance of the sort (since in...
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...4. In the section "Disadvantages of File Processing Systems," the statement is made that the disadvantages of file process- ing systems can also be limitations of databases, depending on how an organization manages its databases. First, why do organizations create multiple databases, not just one all- inclusive database supporting all data processing needs? Second, what organizational and personal factors are at work that might lead an organization to have multiple, independently managed databases(and,hence,not completely follow the database approach)? 6. A driver's license bureau maintains a database of licensed drivers. State whether each of the following represents data or metadata. if it represents data, state whether it is structured or unstructured data. If it represents metadata, state whether it is a fact describing a property of data or a fact describing the context of data. Driver's name, address, and birth date The fact that the driver's name is a 30-character field A photo image of the driver An image of the driver's fingerprint The make and serial number of the scanning device that was used to scan the fingerprint The resolution (in megapixels) of the camera that was used to photograph the driver The fact that the driver's birth date must precede today's date by at least 16 years 17. Draw an ERD for each of the following situations. (If you believe that you need to make additional assumptions, clearly state them for each situation.) Draw the same...
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...Chapter 1 HW Name___________________________________ MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) ________ analyzes the business situation and identify the need for information and information services to meet the problems or opportunities of the business. 1) Database Anaysts A) Database analysts B) Users C) Systems analysts D) Programmers TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 2) Database development projects are never done in a bottom-up fashion. 2) _______ 3) A well-structured database establishes the entities between relationships in order to derive the desired information. 3) _______ ESSAY. Write your answer in the space provided or on a separate sheet of paper. 4) Provide a brief overview of the various components of the database environment. TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 5) Database processing programs are coded and tested during the design stage of the systems development life cycle. 5) _______ MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 6) Organizing the database in computer disk storage is done in the ________ phase. 6) _______ A) analysis B) design C) implementation D) maintenance 7) A workgroup database is stored on a central device called a(n): 7) _______ A) client. B) network. C) server. D) remote...
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...Faculty of Science and Technology ITECH1006/5006 Database Management Systems Database Management Systems Tutorial Week 3 Tasks 1. Given the following table, convert the table into normalised data structure showing all attributes and identifying primary keys. Show your normalisation process from the un-normalised form to the third normal form. 2. Given the following table, convert the above table into normalized data structures showing all attributes and identifying primary keys. Show your normalisation process from the un-normalised form to the third normal form. Customer Number 148 148 282 356 356 408 608 608 608 Customer Name AI’s Appliance and Sport AI’s Appliance and Sport Brookings Direct Ferguson’s Ferguson’s The Everything Shop Johnson’s Department Store Johnson’s Department Store Johnson’s Department Store CRICOS Provider No. 00103D Order Number 21608 Order Date Part Description Iron Number Ordered 11 Quoted Price $21.95 Warehouse 10/20/2007 Part Number AT94 3 Rep Number 20 21619 10/23/2007 DR93 Gas Range 1 $495.00 2 20 21614 10/21/2007 KT03 Dishwasher 2 $595.00 3 35 21610 21610 21613 10/20/2007 10/20/2007 10/21/2007 DR93 DW11 KL62 Gas Range Washer Dryer 1 1 4 $495.00 $399.99 $329.95 2 3 1 65 65 35 21617 10/21/2007 BV06 Howe Gym 2 $794.95 2 65 21617 ...
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...LOVELY PROFESSIONAL UNIVERSITY HOME WORK: 3 School: Department CSE/IT Name of the faculty member: Course No: CSE301 Course Title: Database Management System Class: B.Tech (CSE) Term: 6th Section: D1803 Batch:2008 Max. Marks: 18+7=25 Date of Allotment: Date of Submission: Submitted By: Roll No: 25 PART-A Q-1 What is overlapping of Candidate keys? What are the problems incurred due to this overlap and how these problems can be rectified. Explain with Example. Overlap of candidate key is a type of candidate key which occur in BCNF(Boyce Codd Normal Form). In the difference between 3NF and BCNF example: a 3NF table which doesnot have multiple overlapping candidate keys is gurantted to be in BCNF. Depending on what its functional dependencies are . a 3NF table with two or more overlapping candidate keys may or maynot be in BCNF. Example: The original definition of 1NF was in adequate in some situations. It was not satisfactory for the table: • They had multiple candidate keys • Where the multiple candidate keys were composite • Where the multiple candidate keys overlapped Therefore, a normal form, the BCNF was introduced. We must understand it in tables where...
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