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CUSTOMER_CODE SMUDE DIVISION_CODE SMUDE EVENT_CODE JAN2016 ASSESSMENT_CODE MCA3020_JAN2016 QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 18252 QUESTION_TEXT Discuss Lorel Query Language. Differentiate between XML Oriented Databases and Native XML Databases. SCHEME OF EVALUATION Lorel Query Language:Lorel is considered as an early query language used for semi structured data. Lorel language makes use of the OEM (Object Exchange Model) as the data model for semi structured data. Lorel is utilized to expandOQL (Object Query Language) for the procedure of querying elements. This is done by depending on coercion at various levels to hold back the powerful typing of OQL. Lorel is also used to extend OQL with path expressions. This is done in order that user can state the patterns that are corresponding to actual paths in referred data.(4 marks) One of the advantages of Lorel language is its easy syntax which makes users to understand it more clearly. The drawback of Lorel language is that it is dependent on OQL parser. Also it comprises of limited functionalities. (2 marks) Differences between XML Oriented Databases and Native XML Databases: XML-oriented databases are typically relational and enclose model or pattern driven extensions for transporting data to and from XML documents and are usually intended for data-centric documents. Following are the differences between XML Oriented Databases and Native XML Databases: 1.A native XML database is used to maintain physical structure. An XML-oriented database can do so also, but practice shows a diverse story. 2.Native XML database can accumulate data without schema. We could make use of techniques to recognize structure in unprocessed documents to be accumulated in XML-oriented systems. These types of techniques are relatively limited. 3.XPath, DOM, or comparable XML-associates APIs are required to access data in native XML systems. Alternatively, XML-oriented systems provide direct access to the data via open-standard APIs, like open database connectivity (ODBC). (4 marks) QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 18253 QUESTION_TEXT Explain Temporal Database and Multimedia Database. SCHEME OF EVALUATION Temporal Database: Temporal databases are used to record timereferenced data. Basically, majority of the database technologies are temporal. For example: Record keeping function (inventory administration, medical-record and personnel); Financial function (banking, accounting and portfolio organization); Scientific function (Weather monitoring), Scheduling function (project organization, hotel, airline, and train reservations) all these functions trust on temporal databases. (2 marks) Temporal databases are best suited for the applications where information as to organize on time constraints. Therefore temporal database set a good example to demonstrate the requirement for development of a combined set of concepts for the use of application developers. The training of temporal database is designed by application developers and designers. There are numerous applications where time is an important factor in storing the information. For example: Insurance, Healthcare, Reservation Systems, and Scientific Databases. (2 marks) In case of temporal applications, even the two instances utilized might be simply expanded. For example, in COMPANY database, it might be desirable to keep PROJECT, JOB, and SALARY histories of all the employees. It can be applied to UNIVERSITY database as well, to store the grade history of STUDENT. The details about the YEAR, SEMESTER, COURSE and each SECTION are also included in this database.(1 mark) Multimedia Database: Multimedia databases facilitate the users to store as well as generate query for retrieving multimedia information. This information can demand for: Documents (like articles/books/journals), Images (like drawings/pictures), Video Clips (like newsreels/movies/hone videos); Audio clips (like speeches/ phone messages/ songs).(1 mark) The primary type of database query generally tries to locate multimedia sources comprising of particular objects of interest. Such as, one user wants to locate all the video clips regarding aa specific person, say Michael Jackson in a video database. Another scenario may be as of someone willing to retrieve video clips grounded on specific activities like, video clips where a soccer goal is scored by a certain player or team. These type of queries are mentioned as content based retrieval, as they retrieve information bases on a certain activity/object from the multimedia sources. (2 marks) To make this retrieval fast, the multimedia database must make use of some model to index and manage multimedia sources grounded on the contents. But identifying the contents of multimedia sources is lengthy and difficult task. To accomplish this task, two approaches can be followed as defined below: 1.Based on automatic analysis of the multimedia sources. It is done to recognize the contents mathematical characteristics. 2.Based on manual identification of the objects and objectives of interest in each multimedia source. And later on depending on this information index the sources. (2 marks) QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 73631 QUESTION_TEXT What is an adaptive system? What are the features that make the query processing system to be adaptive? Discuss the applications of adaptive query processing system. SCHEME OF EVALUATION Definition – 2 marks 3 features – 3 marks 5 applications – 1 mark each Adaptive systems are systems that modify their behavior by the use of introspection, learning etc. also known as self tuning or dynamic systems. Features – obtains information from its environment • Applies this information to decide its behavior • This process repeats again and again, resulting in a feedback loop among environment and behavior Applications: • Adaptive query processing in data grids (used to offer better QoS to users and applications in spite of dynamically changing resourecs and environments) • Adaptive query processing in internet applications (efficiently dealing with transfer rates and unpredictable, dynamic data volumes by making use of adaptive query processing techniques) • Adaptive query processing in web based data integration (Mediators for this application requires the capability to handle multiple, often conflicting objectives such as cost, coverage and execution flexibility. This requires the development of adaptive query processing algorithms) • Adaptive query processing in wide area database systems (it is difficult to produce efficient database query plans depending upon information available only at compile time in broad area db systems. Solution is by adusting query plan to varying conditions during execution as well as by making use of information that becomes available at query run time) • To detect and correct optimizer (Adaptive query processing is utilized to detect and correct optimizer errors due to wrong statistics or simplified cost metrics) QUESTION_T DESCRIPTIVE_QUESTION YPE QUESTION_ID 125267 QUESTION_T State the differences between centralized and distributed database. EXT 5 differences ->2 marks each. Any 5 advantages among those mentioned below may be written SCHEME OF EVALUATION QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 125269 QUESTION_TEXT What is denormalization? Explain its techniques. Definition – 2 marks each 4 techniques – 2 marks Denormalization is the process of converting higher normal norms to lower normal forms with the objective of getting faster access to database. SCHEME OF EVALUATION (a) Duplicate data – method of adding duplicate data into relational table. This will minimize the number of joins required to execute a given query. It also minimizes the CPU and I/O resources being utilized as well as boosts up the performance (b) Summary data – records are summarized in some summary columns thereby reducing the number of records stored in a table. This enhances database performance as now the database server needs to process lesser records for a given query execution (c) Horizontal partitioning – table is split by rows thereby reducing the number of records paer table and hence drives the performance (d) Vertical fragmentation – breaks relations by columns. It makes more than 2 tables by allocating the original key to all and allocating a few of the non key columns to every newly made identical keyed table QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 125274 QUESTION_TEXT Explain Fifth Normal Form (5NF). Fifth normal form is the highest normal form used in relational database design. It is mostly used when there is a large relational database. SCHEME OF EVALUATION The fifth normal form has developed by an IBM researcher, Ronald Fagin. According to the Fagin’s theorem, “The original table must be reconstructed from the tables into which it has been decomposed.” 5NF allows decomposing a relation into three or more relations. 5NF is based on the concept of join dependency. Join dependency means that a relation, after being broken down into 3 or more smaller relations, should be capable of being combined all over again on similar key to result in the creation of the original table. The join dependency is more general form of multi-valued dependency. (2 marks) A relation (R) meets the condition of fifth normal form (R1, R2, ……Rn) if and only if R is equal to the join of R1, R2, ……Rn (Here, Ri are subsets of set of attributes of R) Any relation R is said to be in 5NF or PJNF (Project-Join Normal Form) if foe all join dependencies in any case one of the following holds. (a) (R1, R2, ……Rn) is trivial join-dependency (that is one of Rt is R) (b) Every Riis an candidate key for relation R. (2 marks) Definition of Fifth Normal Form: A relation should be in fifth normal form (5NF) if and only if all join dependency in the table is connected by candidate keys of the relation. (2 marks) The table before Fifth Normal Form: The table after Fifth Normal Form: (4 marks)