MBA Database Management Essay

A1.Differentiate among Traditional deposit System & international ampere Modern Database System File Base establishment were the traditional administrations which has been replaced now by modern informationbase clays. All entropybase practical act ar using the Modern day selective informationbase vigilance systems now a days . The difference between the these two technologies given below.File-based SystemFile-based systems were an early strive to computerize the manual filing system. File-based system is a collection of application programs that perform services for the end-users. Each program defines and manages its information. However, five eccentric persons of problem be occurred in using the bill-based apostrophizeSeparation and isolation of dataWhen data is isolated in separate charge ups, it is more difficult for us to find data that should be avail adapted. The application programmer is required to synchronize the bear on of two or more files to ensure t he correct data is extracted. extra of dataWhen employing the decentralized file-based approach, the uncontrolled duplicate of data is occurred. Uncontrolled duplication of data is undesirable becausei.Duplication is wastefulii.Duplication net lead to loss of data integrityData dependenceUsing file-based system, the physical organize and retentivity of the data files and records argon defined in the application program code. This property is known as program-data dependence. Making changes to an existing structure atomic number 18 preferably difficult and depart lead to a modification of program. Such guardianship activities are time-consuming and subject to error.Incompatible file formatsThe structures of the file are dependent on the application programming language. However file structure provided in one programming language such as deport file, indexed-sequential file which is available in COBOL programming, whitethorn be different from the structure generated by different programming language such as C. The reign incompatibility wreaks them difficult to process essencetly.Fixed queries / proliferation of application programsFile-based systems are very dependent upon the application programmer. Any required queries or reports have to be written by the application programmer. Norm altogethery, a contumacious format enquiry or report mass only be entertained and no facility for ad-hoc queries if offered. File-based systems also give tremendous pressure on data processing staff, with users complaints on programs that are inadequate or unable in meeting their demands. Documentation may be limited and guardianship of the system is difficult. Provision for security, integrity and recovery capability is very limited.Database SystemsIn point to overcome the limitations of the file-based approach, the concept of database and the Database Management System (DMS) was emerged in 60s. A database is an application that screwing store and retr ieve data very rapidly. The comparative trash refers to how the data is stored in the database and how it is organized. When we talk about database, we mean a comparative database, in fact an Rdatabase management system Relational Database Management System. In a relational database, tot wholey data is stored in tables. These have the same structure iterate in to all(prenominal) one row (like a spreadsheet) and it is the relations between the tables that make it a relational tableAdvantagesA turning of advantages of applying database approach in application system are obtained including Control of data redundancy The database approach attempts to put across the redundancy by integrating the file. Although the database approach does not eliminate redundancy entirely, it controls the amount of redundancy inherent in the database.Data accordBy eliminating or controlling redundancy, the database approach reduces the risk of inconsistencies occurring. It ensures all copies of the approximation are kept consistent. More information from the same amount of dataWith the integration of the operated data in the database approach, it may be possible to come up additional information for the same data.Sharing of dataDatabase belongs to the entire fundamental law and can be shared by all authorized users. meliorate data integrityDatabase integrity provides the validity and consistency of stored data. Integrity is ordinarily expressed in terms of constraints, which are consistency rules that the database is not permitted to violate. modify securityDatabase approach provides a protection of the data from the unauthorized users. It may prevail the term of user names and passwords to identify user type and their access right in the operation including retrieval, insertion, updating and skip.Enforcement of standardsThe integration of the database enforces the inevitable standards including data formats, naming conventions, documentation standards, update proce dures and access rules.Economy of dental plateCost savings can be obtained by combining all organizations operational data into one database with applications to work on one source of data.Balance of conflicting requirementsBy having a geomorphological design in the database, the conflicts between users or departments can be resolved. Decisions will be based on the base use of resources for the organization as a whole rather that for an individual entity. ameliorate data availableness and responsivenessBy having an integration in the database approach, data accessing can be crossed departmental boundaries. This feature provides more maneuverality and better services to the users.increase productivityThe database approach provides all the low-level file-handling routines. The provision of these functions earmarks the programmer to center more on the specific functionality required by the users. The fourth-generation environment provided by the database can simplify the database application development.Improved maintenanceDatabase approach provides a data independence. As a change of data structure in the database will be affect the application program, it simplifies database application maintenance.Increased concurrencyDatabase can manage concurrent data access effectively. It ensures no interference between users that would not result any loss of information nor loss of integrity.Improved backing and recovery servicesModern database attention system provides facilities to minify the amount of processing that can be lost following a failure by using the transaction approach.DisadvantagesIn split of a intumescent phone fare of advantages can be found in the database approach, it is not without any challenge. The following disadvantages can be found includingComplexityDatabase management system is an extremely complex piece of software. All parties must be familiar with its functionality and take full advantage of it. Therefore, training for the adminis trators, designers and users is required.SizeThe database management system consumes a substantial amount of main memory as well as a large number amount of track record space in ordain to make it run efficiently.Cost of DBMSA multi-user database management system may be very expensive. redden after the installation, there is a high recurrent annual maintenance cost on the software.Cost of conversionWhen moving from a file-base system to a database system, the company is required to have additional expenses on hardware acquisition and training cost.PerformanceAs the database approach is to cater for numerous applications rather than exclusively for a particular one, some applications may not run as fast as before.Higher impact of a failureThe database approach increases the vulnerability of the system due to the centralization. As all users and applications reply on the database availability, the failure of any component can train operations to a halt and affect the services t o the customer mischievouslyQ2. What is the disadvantage of sequential file organization? How do you overcome it? What are the advantages & disadvantages of Dynamic Hashing?Disadvantage of Sequestial file organizationA file that contains records or early(a) elements that are stored in a chronological order based on account number or some other identifying data. In order to rank the desired data, sequential files must be read starting at the beginning of the file. A sequential file may be stored on a sequential access bend such as magnetic tape or on a direct access device such as magnetic disk. phone line with random file.Dynamic HashingAdvantagesThe main advantage of chop upeesh tables over other table data structures is speed. This advantage is more apparent when the number of entries is large (thousands or more). Hash tables are particularly efficient when the maximum number of entries can be predicted in advance, so that the bucket array can be allocated once with the optimum size and never resized.If the preen of pigment- measure pairs is fixed and known ahead of time (so insertions and deletions are not allowed), one may reduce the average lookup cost by a protective(predicate) choice of the chop upisheesh function, bucket table size, and internal data structures. In particular, one may be able to devise a hash function that is collision-free, or even perfect (see below). In this case the keys command not be stored in the table .DisadvantagesHash tables can be more difficult to implement than self-balancing binary pursuit trees. Choosing an effective hash function for a specific application is more an art than a science. In open-addressed hash tables it is fair prosperous to create a sorry hash function.Although operations on a hash table take constant time on average, the cost of a good hash function can be significantly higher than the inner coil of the lookup algorithm for a sequential list or explore tree. Thus hash tables are not effective when the number of entries is very small. (However, in some cases the high cost of computing the hash function can be mitigated by saving the hash value together with the key.)For certain string processing applications, such as spell-checking, hash tables may be less efficient than tries, finite automata, or Judy arrays. Also, if each key is represented by a small enough number of bits, then, instead of a hash table, one may use the key directly as the index into an array of values. Note that there are no collisions in this case.The entries stored in a hash table can be enumerated efficiently (at constant cost per entry), but only in some pseudo-random order. Therefore, there is no efficient way to efficiently locate an entry whose key is nearest to a given key. Listing all n entries in some specific order generally requires a separate sorting step, whose cost is proportional to log(n) per entry. In comparison, arranged search trees have lookup and insertion cost prop ortional to log(n), but allow finding the nearest key at about the same cost, and ordered enumeration of all entries at constant cost per entry.If the keys are not stored (because the hash function is collision-free), there may be no easy way to enumerate the keys that are present in the table at any given moment.Although the average cost per operation is constant and fairly small, the cost of a single operation may be kinda high. In particular, if the hash table uses dynamic resizing, an insertion or deletion operation may occasionally take time proportional to the number of entries. This may be a serious drawback in real-time or interactive applications.Hash tables in general exhibit poor neck of the woods of referencethat is, the data to be accessed is distributed seemingly at random in memory. Because hash tables cause access patterns that jump around, this can trigger microprocessor stash misses that cause long delays. Compact data structures such as arrays, searched with l inear search, may be faster if the table is relatively small and keys are integers or other short strings. According to Moores Law, cache sizes are growing exponentially and so what is considered small may be increasing. The best performance point varies from system to system.Hash tables become quite inefficient when there are many collisions. While extremely uneven hash distributions are extremely unlikely to arise by chance, a spiteful adversary with knowledge of the hash function may be able to supply information to a hash which creates worst-case behavior by create excessive collisions, resulting in very poor performance (i.e., a self-denial of service attack). In critical applications, either universal hashing can be used or a data structure with better worst-case guarantees may be preferableQ3. What is relationship type? Explain the difference among a relationship instance, relationship type & a relation set?A3.A relationship type R among n entity types E1, E2, , En is a set of associations among entities from these types. Actually, R is a set of relationship instances ri where each ri is an n-tuple of entities (e1, e2, , en), and each entity ej in ri is a member of entity type Ej, 1jn. Hence, a relationship type is a mathematical relation on E1, E2, , En, or alternatively it can be defined as a subset of the Cartesian product E1x E2x xEn . Here, entity types E1, E2, , En defines a set of relationship, called relationship sets.Q4. What is SQL? contend.Q5. What is Normalization? Discuss various types of Normal Forms? Q6. What do you mean by Shared ringlet butterfly & Exclusive lock? distinguish briefly two bod locking protocol? MI0034 Database Management System 4 Credits denomination Set- 2 (60 Marks)Answer all the QuestionsQ1. Define Data example & discuss the categories of Data Models? What is the difference between logical data emancipation & Physical Data Independence? Q2. What is a B+ channelises? Describe the structure of b oth internal and leaf nodes of a B+Tree? Q3. Describe Projection operation, Set theoretic operation & join operation? Q4. Discuss Multi Table Queries?Q5. Discuss Transaction Processing concept? 10.2 Describe properties of Transactions? Q6. Describe the advantage of Distributed database? What is Client/server Model? Discuss briefly the security and Internet violation? .