Baze Podataka K1 - Teorijski Deo

The primary key of a relation can consist of multiple attributes. This means that it is not limited to just one attribute but can be made up of a combination of multiple attributes. This allows for more flexibility in defining the primary key for a relation and ensures uniqueness of the records in the relation.

The given answer is correct because it accurately describes the purpose and function of the organization's database. It states that the database supports all the processes of the organization and the decision-making process. This implies that the database is comprehensive and covers all aspects of the organization's operations. The answer also does not mention anything about the size or location of the database, as these details are not provided in the question.

The correct answer is "Procesi koji se dalje ne mogu dekomponovati. Dalja dekompozicija se svodi na instrukcije programa." This means that primitive processes are processes that cannot be further decomposed and their decomposition is reduced to program instructions. In other words, these processes are not further divisible and their execution is carried out through a sequence of program instructions.

The correct answer is that a strong object identifies a weak object and a weak object existsentially depends on a strong object. This means that the strong object is able to recognize or reference the weak object, while the weak object relies on the existence of the strong object for its own existence.

Edgar F. Codd is the correct answer because he was a scientist who defined the principles of relational databases. He introduced the concept of organizing data into tables with rows and columns, and developed the relational model which forms the basis of modern database management systems. His work revolutionized the field of database management and laid the foundation for the structured query language (SQL) used in relational databases today.

In a hierarchical data model, a record cannot be added to a child table until it is included in the parent table. This means that in order for a record to exist in a child table, it must have a corresponding record in the parent table. This ensures that the relationship between the parent and child tables is maintained and that data integrity is preserved.

A primary key in a relation can consist of multiple attributes. This means that the primary key can be formed by combining two or more attributes to uniquely identify a record in the table.

The characteristic of attributes in a DOV diagram is that the number of attributes for one object is not limited. This means that an object in a DOV diagram can have any number of attributes associated with it, making it flexible and adaptable to different scenarios.

When using the specialization feature in a DOV diagram, the object that is being specialized transfers its attributes to the newly created objects. This means that the attributes of the original object are inherited by the specialized objects. This allows the specialized objects to have the same attributes as the original object, but potentially with additional attributes specific to their specialization.

The given answer states that the model is simple, there is a high redundancy of data, and anomalies occur during updates. This suggests that the database is implemented as a single table, which leads to data duplication and inconsistencies when updating the data. The simplicity of the model may make maintenance easier, but the presence of data redundancy and update anomalies can lead to errors and inconsistencies in the database.

The correct answer is "Interfejs između korisnika (korisničkih programa, aplikacija) i zapisa baze podataka na disku". This answer is correct because a database management system (DBMS) acts as an interface between the user and the database stored on the disk. It allows users to interact with the database by providing functionalities such as querying, updating, and managing data. The DBMS handles tasks like memory management, buffering, indexing, and pointers to ensure efficient data management.

In MOV models, objects can represent both real-world objects and abstract concepts. This means that the objects in the model can be concrete entities that exist in the real world, as well as abstract ideas or concepts that cannot be physically touched or seen. The model captures both tangible and intangible entities, allowing for a comprehensive representation of the system being modeled.

The correct answer is "Velika redudansa podataka" (High data redundancy). In a classic file-based system, data redundancy is typically high. This means that there is a lot of duplication of data, leading to wastage of storage space. This redundancy can result in data inconsistencies and difficulties in maintaining data integrity.

Dijagrami tokova podataka (DTP) opisuju tokove podataka i informacija u sistemu. They provide a visual representation of how data moves through a system, including inputs, outputs, and processes. DTPs are commonly used in systems analysis and design to understand and communicate the flow of information within an organization or system. They help identify data sources, data transformations, and data destinations, making it easier to analyze and improve system efficiency and effectiveness.

The given statement suggests that the relation r defined over the relation R can have zero tuples. This means that there may not be any tuples present in the relation r.

The answer is correct because it states that the tuples must be unique, meaning that there cannot be any duplicate tuples in the relation. Additionally, it mentions that the order in which the tuples are entered is not important, indicating that the relation is not ordered based on the tuple input sequence.

The attribute can take a NULL value in the following cases: when the value of the attribute is not known at the time of input and when the value of the attribute does not make sense.

The correct answer is "Svaki podskup atributa te šeme koji je povezuje sa drugom relacijom" which translates to "Every subset of attributes of this schema that connects it to another relation." This answer correctly defines the foreign key in a relation as a subset of attributes that establishes a connection with another relation.

In the process of modeling, an object from the real world must have at least one attribute. This means that it should have at least one characteristic or property that can be described or represented. Without any attributes, the object would not have any defining features or information associated with it, making it difficult to model or represent accurately. Therefore, having at least one attribute is essential in the modeling process.

The physical design of a database is important for efficient query execution. By optimizing the physical layout of the database, such as indexing and partitioning, the system can retrieve and process data more quickly, resulting in faster query execution times. This is crucial for applications that require real-time or near-real-time responses. Without proper physical design, queries may take longer to execute, leading to poor performance and user dissatisfaction. Therefore, ensuring efficient query execution is a key reason why physical database design is important.

The correct answer states that the development process of an information system is not completed when it is introduced into use, but rather continues with the addition of new software modules and the modernization of existing functionalities. This implies that the iterative (cyclic, spiral) approach to building an information system allows for ongoing improvements and updates to be made even after the system is implemented. This characteristic makes the approach flexible and adaptable to changing needs and requirements.

The correct answer is Edgar Codd. Edgar Codd is credited with establishing the theoretical foundations of the relational model of data in 1970. His work laid the groundwork for the modern relational database management systems that are widely used today. Codd's contributions revolutionized the field of database management and his ideas continue to be influential in the design and implementation of database systems.

The correct answer includes three components of the relational data model: strukturna (structural) component, integritetska (integrity) component, and manipulativna (manipulative) component. These components are fundamental to the relational model and are necessary for organizing and managing data in a relational database system. The structural component defines the structure and organization of the data, the integrity component ensures the accuracy and consistency of the data, and the manipulative component allows for querying, inserting, updating, and deleting data in the database.

The correct answer is r={(2,4); (3,6); (4,8)}. This is because the relation A´B is defined as {(a,b) | a=b/2}, which means that for every element a in A, there is an element b in B such that b is equal to a divided by 2. Looking at the given sets A={1,2,3,4} and B={4,6,8}, we can see that the only elements in A that satisfy the condition are 2, 3, and 4. For these elements, the corresponding elements in B are 4, 6, and 8 respectively. Therefore, the relation r={(2,4); (3,6); (4,8)} is the correct answer.

The correct answer is: Svaki podskup atributa te šeme koji ima osobinu da jednoznačno odredjuje n-torke relacije, a da ni jedan njegov pravi podskup nema tu osobinu.

The answer correctly defines the concept of a candidate key in a relation. A candidate key is a subset of attributes in a relation that uniquely determines the tuples in the relation, and no proper subset of it has this property.

The correct answer is "Visoka kompleksnost i težina upotrebe". This is because the basic characteristic of a network data model is its high complexity and difficulty of use. This means that it can be challenging to understand and manipulate the data within a network data model.

The correct answer is "Uočavanje entiteta, atributa, ograničenja i njihovu grafičku predstavu." This answer refers to the concept of object-relationship modeling, which involves identifying entities, attributes, constraints, and their graphical representation. It is a process used in database design to create a visual representation of the relationships between different elements of a system.

Structural System Analysis (SSA) is an approach in the development of business information systems where data flows within the system are analyzed, key entities and their attributes are determined, as well as entities outside the system with which it communicates. It focuses on analyzing data flows, identifying key entities and their attributes, and understanding the system's communication with external entities.

The correct answer is "Strukturna, integritetska i manipulativna." These terms refer to different components of a relational data model. The "strukturna" component refers to the structure or organization of the data, including tables, fields, and relationships between them. The "integritetska" component refers to the integrity constraints that ensure the accuracy and consistency of the data, such as primary key constraints and referential integrity. The "manipulativna" component refers to the operations or actions that can be performed on the data, such as inserting, updating, and deleting records.

The activities of deleting and updating existing tuples can disrupt referential integrity because they can result in orphaned or inconsistent data. When a tuple is deleted or updated, any references to that tuple from other tables may become invalid or meaningless. This can lead to data integrity issues and inconsistencies in the database. Therefore, these activities need to be carefully managed and coordinated to maintain the referential integrity of the database.

The given answer suggests that the specification of referential integrity allows for a NULL value to be entered for the attribute SifNad. This means that it is not mandatory to have a value for SifNad in the Radnik table. However, it does not specify anything about the attribute SifR, so it is unclear whether a NULL value can be entered for SifR or not based on the given information.

Baze podataka su integrisani skup podataka o nekom sistemu i skup postupaka za njihovo korišćenje i održavanje. To znači da baza podataka sadrži organizovane informacije o nekom sistemu, kao i set instrukcija i procedura za pristupanje tim podacima, njihovo korišćenje i održavanje. Baza podataka omogućava efikasno upravljanje i manipulaciju podacima, kao i deljenje informacija među korisnicima sistema.

The correct answer is "To je skup međusobno povezanih tabela." This means that a data store in a data flow diagram (DFD) represents a set of mutually connected tables. In other words, it represents a collection of tables that are related to each other in some way.

The correct answer is "Sloj koji obuhvata šeme modela podataka, sve relacije i ograničenja nad bazom". This answer accurately describes the conceptual layer in a three-tier architecture of a database. The conceptual layer is responsible for defining the overall structure of the database, including the data models, relationships between entities, and constraints imposed on the data. It acts as an intermediary between the application layer and the physical storage layer of the database.

The characteristic of the waterfall methodology in the development of an information system is a segmented approach in analysis, design, testing, implementation, and maintenance of the system. This means that each phase of the development process is completed before moving on to the next phase, ensuring a systematic and organized approach to building the system. This approach allows for better control and management of the project, as well as easier identification and resolution of issues at each stage. It also ensures that the system is thoroughly tested and stable before being implemented.

The given relation A´B={(a,b) | a=b+1} states that the elements in set A are related to the elements in set B such that each element in A is equal to the corresponding element in B minus 1. Therefore, the correct answer r={(2,1); (3,2)} satisfies this relation, as 2 is equal to 1+1 and 3 is equal to 2+1.

In this statement, it is mentioned that if articles are procured from different suppliers, then the articles are a weak entity and the suppliers are a strong entity. This means that the existence of an article depends on the existence of a supplier, making it a weak entity. On the other hand, the suppliers can exist independently, making them a strong entity.

If there are too many attributes in the modeling process, it means that the credibility of the model is excellent, the complexity is high, the manipulations are difficult, and the obtained information is confusing.

A contextual diagram is a data flow diagram (DTP) that represents the entire system as a single process, often depicted as a black box. It shows the flow of data between various entities and processes in the system. This diagram helps in understanding the overall structure and interactions within the system.

The correct answer is "Ceo broj" and "Broj od 5 do 10". This means that the attribute "ocena" can have values that are whole numbers and that range from 5 to 10.

The cardinality of a relation determines the number of tuples (n-tuples) in that relation.

The correct answer states that a super key of a relation is any subset of attributes of the schema that uniquely determines the n-tuples in the relation. This means that the combination of attributes in the super key must be able to uniquely identify each tuple in the relation.

The explanation for the given correct answer is that the description of primitive processes is done in a natural language, such as spoken language, pseudocode, or fragments of a higher-level programming language. This means that the logic of primitive processes can be expressed in a way that is easily understandable by humans, either through verbal communication or through written instructions that resemble code but are not necessarily bound by strict syntax rules.

The correct answer is "PROFESORI su slab entitet, ZAPOSLENI su jak entitet." This means that "PROFESORI" (professors) are a weak entity, while "ZAPOSLENI" (employees) are a strong entity. This implies that professors are dependent on the existence of employees, but employees can exist independently without being professors.

The primary key of a relation is a unique identifier for each record in the table. It is used to uniquely identify each row in the table and ensure that there are no duplicate records. The primary key is essential for maintaining data integrity and for establishing relationships with other tables through foreign keys.

The specialization in an ER (Entity-Relationship) diagram represents the specific cases of one entity, also known as concretization. It allows for the identification and representation of unique characteristics or attributes of a particular subset of the entity. This helps in organizing and categorizing data in a more structured manner, enabling better understanding and analysis of the system being modeled.

The given answer states that a foreign key can be part of the primary key of the same relation. This means that the value of the foreign key can also be used as part of the primary key, which helps in establishing a relationship between two tables. This is a characteristic of a foreign key in a relational database.

The correct answer is "Entiteti (objekti) iz realnog sveta koji okružuje sistem." This is because in data flow diagram (DFD), entities represent the external entities or objects in the real world that interact with the system being analyzed. They can be people, organizations, or other systems that provide inputs or receive outputs from the system. These entities are important to consider in order to understand the system's external interactions and dependencies.

The correct answer is the layer to which applications refer, i.e. the corresponding user model of the database. This layer acts as an interface between the applications and the underlying database, allowing the applications to interact with the database using a user-friendly model that is tailored to their needs.

The correct answer is the layer of the database that is responsible for storing the conceptual layer on a storage medium. This layer is responsible for physically storing the data in the database, converting it into a format that can be stored and retrieved efficiently. It is the lowest level of the three-layer architecture and is not directly accessed by applications or users.

Object-relationship diagrams are important for overall and accurate modeling of an organization. These diagrams help to visually represent the relationships between different objects in an organization, such as entities, attributes, and their connections. By creating these diagrams, organizations can gain a better understanding of their structure, processes, and interactions, which in turn can lead to more effective decision-making, improved communication, and better overall organization.

This answer suggests that in a database system, there is little to no redundancy of data. Redundancy refers to the duplication of data, which can lead to inconsistencies and inefficiencies in the database. By minimizing or eliminating redundancy, the database can ensure that each piece of data is stored only once, improving data integrity and reducing storage requirements.

The correct answer includes three components: "Brz dizajn" (Fast design), "Osnovna primena SQL-a" (Basic implementation of SQL), and "Slozeno programiranje" (Complex programming). These three elements are important in the development of business applications. Fast design refers to quickly creating the initial design of the application. Basic implementation of SQL involves using SQL (Structured Query Language) to interact with databases. Complex programming refers to writing intricate code to handle more advanced functionalities in the application.

This answer is correct because it accurately describes the concept of "Opis prava pojedinih korisnika" which translates to "Description of individual user rights". This concept refers to the explanation or documentation of the specific permissions and privileges that each user has within a system or application. It outlines what actions or operations a user is allowed to perform, what data they can access, and any restrictions or limitations placed on their activities.

The correct answer is "Konceptualni model ne propisuje fizički oblik podataka na hard disku". This means that the conceptual model does not dictate the physical form of data on a hard disk. The conceptual model is a high-level representation of how data is organized and structured, while the physical form refers to the actual arrangement of data on a storage device. The physical form is determined by factors such as the file system and hardware implementation, and it is not directly influenced by the conceptual model.

The correct answer is "Izbor odgovarajućeg SUBP" because selecting the appropriate SUBP (Software Underlying Business Process) is not a part of the Structural System Analysis (SSA) methodology. SSA focuses on functional decomposition, data flow diagrams, and data dictionaries to analyze and model the system's structure. Selecting the appropriate SUBP is more related to software design or implementation rather than system analysis.

The correct answer is "Smanjena je potreba za održavanjem aplikacija" (The need for maintaining applications has decreased). This is because in the context of a database system, the implementation of a centralized and structured database reduces the need for application maintenance. With a well-designed and efficient database system, applications can access and manipulate data easily, without requiring frequent updates or maintenance.

During the 1990s, there was a wide application of network databases, which allowed for efficient storage and retrieval of data across different systems. Additionally, there was a significant development of applications based on the World Wide Web (WWW), Internet, and database foundations (DB). This led to the creation of web-based applications that could access and manipulate data from databases through the internet. Furthermore, the emergence of multimedia data became prominent during this time, as databases started to support the storage and retrieval of various types of media such as images, audio, and video.

A good scenario in the development of business applications involves a detailed design, complete implementation of SQL, and simple programming. This means that a thorough and well-thought-out design is necessary to ensure that all requirements are met. Additionally, the complete implementation of SQL allows for efficient and effective data management and manipulation. Lastly, using simple programming techniques helps in creating clean and maintainable code.

The correct answer is "Može da poprimi vrednost primarnog ključa u ciljnoj relaciji" and "Može da poprimi NULL vrednost". This means that the foreign key in a relationship can take on the value of the primary key in the target relation or it can be NULL.

The given answer includes the keywords "CASCADES", "RESTRICTED", and "NULLS". These keywords are commonly used in the context of dynamic specification of referential integrity. "CASCADES" refers to the action of cascading updates or deletes to related records. "RESTRICTED" indicates that the referential integrity constraint restricts updates or deletes if there are related records. "NULLS" suggests that null values are allowed in the foreign key column. Therefore, these keywords are relevant to the dynamic specification of referential integrity.

In the process of modeling, a relationship between objects from the real world should have a minimum of two attributes. This means that in order to accurately represent the relationship between objects, at least two characteristics or properties need to be considered. Having only one attribute would not provide enough information to fully describe the relationship, and having zero attributes would mean there is no information or connection between the objects. Three attributes or more would provide additional details but are not necessary for the minimum requirement of establishing a relationship.

The correct answer is the first option, "Nakon funkcionalne dekompozicije i definisanja tokova podataka i njihove strukture." This is because after the functional decomposition and defining the data flows and their structure, it is necessary to describe the logic of primitive processes. This implies that the logic of primitive processes is described after the functional decomposition and data flow definition.

The correct answer is "Preko procesa". This means that the U SSA analysis interfaces interact with data stores through processes. This suggests that there is a separate process that handles the communication between the analysis interfaces and the data stores. It is likely that this process acts as a mediator or controller, facilitating the exchange of data between the interfaces and the data stores.

The correct answer is "Odnos broja objekata koji se povezuju." This means that the cardinality in a DOV diagram refers to the relationship between the number of objects that are connected to each other. It represents how many objects are involved in a particular relationship, such as binary (two objects) or unary (one object).

The given correct answer is "Dijagrami funkcionalne dekompozicije jednog sistema od vrha na dole". This answer suggests that the diagrams in question are used to decompose a system from top to bottom, breaking it down into smaller functional components. This type of diagram helps to visualize the hierarchical structure of a system and understand how the different components interact with each other. It is a useful tool for system analysis and design.

The correct answer is "Predstavljaju specifičnu poslovnu aktivnost u jednoj organizaciji." This is because data flow processes in data flow diagrams represent specific business activities within an organization. These processes show how data is transformed or manipulated within the system to achieve a specific goal or outcome.

The correct answer includes the data that is being stored in the student database. It includes the grades of students in different subjects, their place of residence (address), student ID number, average grade of the student, average grade of the students in the current year of study, and the average grade of all students at the faculty. Additionally, it includes a feature to view students who are from Belgrade.

Aggregation in the ER (Entity-Relationship) diagram is a relationship between two entities where one entity is considered as a whole and the other entity is considered as a part. It is represented by a diamond-shaped line connecting the entities. The entity acting as a whole is called the aggregate and the entity acting as a part is called the component. The component entity can participate in other relationships as well, just like any other entity.

The given answer correctly states two characteristics of the RBP relation. The first characteristic is that the attribute names must be different, meaning that no two attributes can have the same name. This ensures uniqueness and avoids confusion in the relation. The second characteristic is that the relation schema must contain at least one attribute. This requirement ensures that the relation has some meaningful data to represent.

The correct answer includes three main functions of a database management system (DBMS). Firstly, it is responsible for creating a database and its objects, such as tables, indexes, and views. Secondly, it handles the maintenance and manipulation of data, allowing users to insert, update, delete, and retrieve data from the database. Lastly, it ensures control and access rights to the data in the database, ensuring that only authorized users can access and modify the data.

In classical data processing systems based on files and programming languages, it is impossible to read a file without its definition. Additionally, it is difficult (sometimes even impossible) to provide support for concurrent operations. This means that without knowing the structure and format of a file, it is not possible to access its data, and implementing concurrent operations in such systems can be challenging or not feasible.

Podatak u bazi podataka je vrednost koja se upisuje u promenljivu određenog tipa i cinjenica o nekom predmetu i/ili događaju koja se može zabeležiti i sačuvati na računaru.

The correct answer suggests that there is a dependency or relationship between applications and data. This means that the functioning or behavior of applications is influenced by the data they are working with. In other words, the applications rely on the data to perform their tasks effectively.

The correct answer is a list of techniques for gathering information about user requirements in the design of an information system. These techniques include studying documentation, conducting interviews, using questionnaires, observing work in the environment, and conducting research.

The correct answer states that there cannot be two identical tuples in a relation. This means that each tuple in the relation must have a unique combination of attribute values. This property ensures that each tuple can be uniquely identified and distinguishes it from other tuples in the relation. It is a fundamental aspect of maintaining data integrity and ensuring the accuracy and consistency of the data stored in the relation.

The given correct answer is "Početak implementacije sistema". This answer suggests that the description of primitive processes represents the beginning of the system implementation. This implies that the primitive processes are the initial steps or actions taken in the implementation phase of a system. The other options, such as the description of functional decomposition, data flow in the system, and defining structure, fields, domains, and constraints, do not directly relate to the implementation phase.

Functional diagrams primarily focus on analyzing and data flows in the construction of an information system. They relate to both data and processes, as well as functions within organizations. They show the flow of data within an organization, based on which the corresponding software modules are developed and implemented. However, functional diagrams do not deal with the data that already exists in the system, but rather emphasize the importance and complexity of individual business functions.

The correct answer is "Organizovani skup logički povezanih podataka, koji se održava i koje koristi više korisnika ili programa". This option accurately describes a database as a organized collection of logically connected data that is maintained and used by multiple users or programs. Additionally, the option "Skup podataka koji se odrzava i koji koriste vise korisnika ili programa" is also correct as it conveys the same meaning.

In the context of the given question, the correct answer states that one of the characteristics of specialization in DOV diagrams is avoiding the input of NULL values. This means that when creating a DOV diagram, it is preferred to have non-null values for the attributes, as NULL values can create ambiguity and make it difficult to interpret the diagram accurately. By avoiding NULL values, the diagram becomes more reliable and easier to understand.

The iterative approach allows for quick implementation of the system, meaning that it can be introduced into usage rapidly. On the other hand, the development of the system continues as long as the system is alive, allowing for ongoing improvements and updates. This approach also allows for changes in business requirements during the implementation process. However, it does not provide precise time and cost estimates for the introduction of the system into usage.

This answer correctly states that a foreign key can only take on the value of the primary key in the target relation or a NULL value. This is a key principle of referential integrity, which ensures that relationships between tables are maintained and that data remains consistent.

The correct answer is "Sve interfejse sa kojima sistem komunicira" (All interfaces with which the system communicates). In SSA analysis, a contextual diagram defines all the interfaces or connections that the system has with external entities. It provides an overview of how the system interacts with its environment and helps identify the inputs and outputs of the system. This diagram is used to understand the system's boundaries and its interactions with other systems or entities.

Minimalna kardinalnost veze oznacava minimalan broj instanci entiteta koji moraju da ucestvuju u vezi. This means that there is a minimum number of instances of an entity that must participate in the relationship.

In the 1980s, the characteristics of databases included the widespread use of network databases, the application of ER modeling, client-server processing, and the use of graphical user interfaces. These characteristics were prominent during that time period and represented advancements in database technology.

The correct answer is "Maksimalan broj entiteta koji ucestvuju u ostvarivanju veze" which translates to "The maximum number of entities that participate in establishing the relationship." This means that the maximum cardinality of a relationship refers to the maximum number of entities that can be involved in that relationship.

The characteristics of the waterfall technology compared to the iterative approach in the development of information systems are that each individual activity is approved before the start of the next one, there is a high degree of cost control, and the system development is precisely defined in terms of time. This means that in the waterfall model, each phase of the development process must be completed and approved before moving on to the next phase, ensuring a systematic and controlled approach. Additionally, the waterfall model allows for better cost control and a clear timeline for the development process.

The correct answer is "Broj domena nad kojima je definisana relacija" which translates to "The number of domains over which the relation is defined." This means that the stepen relacije r determines the number of different domains that the relation is defined on.

Informacija je skup podataka koji su obrađeni u bazi podataka. Obrada podataka u bazi podataka rezultira stvaranjem informacija koje mogu biti korisne i relevantne za korisnike. Ova definicija naglašava da informacija nije samo skup sirovih podataka, već podaci koji su obrađeni i organizirani na način koji omogućava korisnicima da dobiju znanje ili razumijevanje iz tih podataka.