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e-office-Databases.pptx

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Electronic office (Office automation) Electronic office (Office automation)

ELECTRONIC OFFICE (OFFICE AUTOMATION) The concept of the electronic office (office automation) encompasses the ELECTRONIC OFFICE (OFFICE AUTOMATION) The concept of the electronic office (office automation) encompasses the application of computer and communications technology to improve the productivity of all types of office workers, including clerical, administrative, professional, and executive. In the mid-1950 s, office automation was used as a synonym for data processing and referred to the ways in which bookkeeping tasks were automated. After some years of disuse, the term was revived in the mid-1970 s to describe the interactive use of word and text processing systems, which would later be combined with powerful computer tools leading to a so-called "office of the future" that, inevitably, would be an electronic office.

The definition of electronic office is not precise, and it might be either: • The definition of electronic office is not precise, and it might be either: • the introduction of individual computers running office software applications, such as word processors, • or the interconnection of office computers using a local area network (LAN), • or the centralization of office functions via web applications.

 • The introduction of e-office improved accuracy and efficiency of organizations and thereby • The introduction of e-office improved accuracy and efficiency of organizations and thereby improved their level of service, while theoretically lowering costs and drastically reducing the consumption of paper. Many documents are still being printed out and circulated on paper, however, especially the ones that require signature. • A word processor is a computer application used for the production (including composition, editing, formatting, and possibly printing) of any sort of printable material.

Word processors Microsoft Word is the most widely used word processing software. Microsoft estimates Word processors Microsoft Word is the most widely used word processing software. Microsoft estimates that over 500, 000 people use the Microsoft Office suite, which includes Word. Many other word processing applications exist, including Word. Perfect (which dominated the market from the mid-1980 s to early-1990 s on computers running Microsoft's MS-DOS operating system) and open source applications Open. Office. org Writer, Libre. Office Writer, Abi. Word, KWord, and Ly. X. Web-based word processors, such as Office Web Apps or Google Docs, are a relatively new category.

Typical functions: - batch mailings using a form letter template and an address database Typical functions: - batch mailings using a form letter template and an address database (also called mail merging); - indices of keywords and their page numbers; - tables of contents with section titles and their page numbers; - tables of figures with caption titles and their page numbers; - cross-referencing with section or page numbers; - footnote numbering; - new versions of a document using variables (e. g. model numbers, product names, etc. )

 • Other word processing functions include spell checking (actually checks against wordlists), • Other word processing functions include spell checking (actually checks against wordlists), "grammar checking" (checks for what seem to be simple grammar errors), and a "thesaurus" function (finds words with similar or opposite meanings). Other common features include collaborative editing, comments and annotations, support for images and diagrams and internal cross-referencing. • Most current word processors can calculate various statistics pertaining to a document. These usually include: • Character count, word count, sentence count, line count, paragraph count, page count. • Word, sentence and paragraph length. • Editing time.

Business • Within the business world, word processors are extremely useful tools. Typical uses Business • Within the business world, word processors are extremely useful tools. Typical uses include: - legal copies letters and letterhead (фирменный бланк) memos reference documents • Businesses tend to have their own format and style for any of these. Thus, versatile word processors with layout editing and similar capabilities find widespread use in most businesses

Databases Databases

A database is an organized collection of related information used for a specific purpose, A database is an organized collection of related information used for a specific purpose, such as keeping track of ongoing work order activities or maintaining a library.

Data Base Management System (DBMS) DBMS is a set of computer programs that controls Data Base Management System (DBMS) DBMS is a set of computer programs that controls the – creation, – maintenance, and – use of a database.

Database management systems A database management system (DBMS) consists of software that operates databases, Database management systems A database management system (DBMS) consists of software that operates databases, providing • storage, • access, • security, • backup and • other facilities.

Examples of some commonly used DBMS • • • My. SQL, Postgre. SQL, Microsoft Examples of some commonly used DBMS • • • My. SQL, Postgre. SQL, Microsoft Access, SQL Server, File. Maker, Oracle, RDBMS, d. BASE, Clipper, Fox. Pro, etc. Almost every database software comes with an Open Database Connectivity (ODBC) driver that allows the database to integrate with other databases.

Database management systems can be categorized according to the database model that they support, Database management systems can be categorized according to the database model that they support, such as relational or XML, the query language(s) that access the database, such as SQL or XQuery, the type(s) of computer they support, such as a server cluster or a mobile phone, performance trade-offs, such as maximum scale or maximum speed or others.

Also databases can be classified by function and database model I. Function Analytic(al) Operational Also databases can be classified by function and database model I. Function Analytic(al) Operational ……. . II. Database model Flat file Hierarchical Network Relational

I Analytical Databases An analytical database is used to store information from different types I Analytical Databases An analytical database is used to store information from different types of databases such as selected operational databases and external databases. Other names given to analytical databases are information databases, management databases or multidimensional databases. The data stored in an analytical database is used by the management for analysis purposes, hence the name. The data in an analytical database cannot be changed or manipulated.

Operational Databases In its day to day operation, an organization generates a huge amount Operational Databases In its day to day operation, an organization generates a huge amount of data. Think of things such as inventory management, purchases, transactions and financials. All this data is collected in a database which is often known by several names such as operational/ production database, subject-area database (SADB) or transaction databases. An operational database is usually hugely important to organisations as they include the customer database, personal database and inventory database i. e. the details of how much of a product the company has as well as information on the customers who buy them. The data stored in operational databases can be changed and manipulated depending on what the company requires.

ALSO Databases can be called as follows … ALSO Databases can be called as follows …

Database Warehouses Organisations are required to keep all relevant data for several years. In Database Warehouses Organisations are required to keep all relevant data for several years. In the UK it can be as long as 6 years. This data is also an important source of information for analysing and comparing the current year data with that of the past years which also makes it easier to determine key trends taking place. All this data from previous years are stored in a database warehouse. Since the data stored has gone through all kinds of screening, editing and integration it does not need any further editing or alteration. With this database ensure that the software requirements specification (SRS) is formally approved as part of the project quality plan

Distributed Databases Many organisations have several office locations, manufacturing plants, regional offices, branch offices Distributed Databases Many organisations have several office locations, manufacturing plants, regional offices, branch offices and a head office at different geographic locations. Each of these work groups may have their own database which together will form the main database of the company. This is known as a distributed database.

End-User Databases There is a variety of data available at the workstation of all End-User Databases There is a variety of data available at the workstation of all the end users of any organization. Each workstation is like a small database in itself which includes data in spreadsheets, presentations, word files, note pads and downloaded files. All such small databases form a different type of database called the end-user database.

External Database There is a sea of information available outside world which is required External Database There is a sea of information available outside world which is required by an organization. They are privately-owned data for which one can have conditional and limited access for a fortune. This data is meant for commercial usage. All such databases outside the organisation which are of use and limited access are together called external database.

Hypermedia Database Most websites have various interconnected multimedia pages which might include text, video Hypermedia Database Most websites have various interconnected multimedia pages which might include text, video clips, audio clips, photographs and graphics. These all need to be stored and “called” from somewhere when the webpage if created. All of them together form the hypermedia database.

Navigational Database Navigational database has all the items which are references from other objects. Navigational Database Navigational database has all the items which are references from other objects. In this, one has to navigate from one reference to other or one object to other. It might be using modern systems like XPath. One of its applications is the air flight management systems.

Document-Oriented Database A document oriented database is a different type of database which is Document-Oriented Database A document oriented database is a different type of database which is used in applications which are document oriented. The data is stored in the form of text records instead of being stored in a data table as usually happens.

Real-Time Database A real-time database handles data which constantly keep on changing. An example Real-Time Database A real-time database handles data which constantly keep on changing. An example of this is a stock market database where the value of shares change every minute and need to be updated in the real-time database. This type of database is also used in medical and scientific analysis, banking, accounting, process control, reservation systems etc. Essentially anything which requires access to fast moving and constantly changing information. Assume that this will require much more time than a normal relational database when it comes to the software testing life cycle, as these are much more complicated to efficiently test within normal timeframes.

II Database models What is a data model? Essentially a data model is a II Database models What is a data model? Essentially a data model is a "description" of both a container for data and a methodology for storing and retrieving data from that container. Actually, there isn't really a data model "thing". Data models are abstractions, oftentimes mathematical algorithms and concepts. You cannot really touch a data model. But nevertheless, they are very useful. The analysis and design of data models has been the cornerstone of the evolution of databases. As models have advanced so has database efficiency.

Flat file database model is a database that stores data in a plain text Flat file database model is a database that stores data in a plain text file. Each line of the text file holds one record, with fields separated by delimiters, such as commas or tabs. Such flatfile database would store an excessive amount of redundant data. Name Address Course Grade Mr. Eric Tachibana 123 Kensigton Chemistry 102 C+ Mr. Eric Tachibana 123 Kensigton Chinese 3 A Mr. Eric Tachibana 122 Kensigton Data Structures B Mr. Eric Tachibana 123 Kensigton English 101 A Ms. Tonya Lippert 88 West 1 st St. Psychology 101 A Mrs. Tonya Ducovney 100 Capitol Ln. Psychology 102 A Ms. Tonya Lippert 88 West 1 st St. Human Cultures A Ms. Tonya Lippert 88 West 1 st St. European Governments A

Hierarchical database model • Perhaps the most intuitive way to visualize this type of Hierarchical database model • Perhaps the most intuitive way to visualize this type of relationship is by visualizing an upside down tree of data. In this tree, a single table acts as the "root" of the database from which other tables "branch" out. • Relationships in such a system are thought of in terms of children and parents such that a child may only have one parent but a parent can have multiple children. Parents and children are tied together by links called "pointers" • The hierarchical structure is used primarily today for storing geographic information and file systems.

Hierarchical database model Hierarchical database model

Network database model The Network model solves the problem of data redundancy by representing Network database model The Network model solves the problem of data redundancy by representing relationships in terms of sets (множества) rather than hierarchy. The network model is very similar to the hierarchical model actually. In fact, the hierarchical model is a subset of the network model. However, instead of using a single-parent tree hierarchy, the network model uses set theory to provide a tree-like hierarchy with the exception that child tables were allowed to have more than one parent. This allowed the network model to support many-to-many relationships.

Network database model Network database model

Nevertheless, though it was a dramatic improvement, the network model was far from perfect. Nevertheless, though it was a dramatic improvement, the network model was far from perfect. Most profoundly, the model was difficult to implement and maintain. Most implementations of the network model were used by computer programmers rather than real users. What was needed was a simple model which could be used by real end users to solve real problems.

Relational database model • • • In the 80's the Relational database model • • • In the 80's the "Relational Database Model" became the rage. The Relational Model developed out of the work done by Dr. E. F. Codd at IBM in the late 1960 s who was looking for ways to solve the problems with the existing models. Because he was a mathematician, he naturally built the model on mathematical concepts which he expounded in the famous work called "A Relational Model of Data for Large Shared Databanks". At the core of the relational model is the concept of a table (also called a relation) in which all data is stored. Each table is made up of records (horizontal rows also known as tuples) and fields (vertical columns also known as attributes). • It is important to note that how or where the tables of data are stored makes no difference. Each table can be identified by a unique name and that name can be used by the database to find the table behind the scenes. As a user, all you need to know is the table name in order to use it. You do not need to worry about the complexities of how the data is stored on the hard drive. • • This is quite a bit different from the hierarchical and network models in which the user had to have an understanding of how the data was structured within the database in order to retrieve, insert, update, or delete records from the database.

Relational database model Relational database model

The relational structure is the most commonly used today. It is used by mainframe, The relational structure is the most commonly used today. It is used by mainframe, midrange and microcomputer systems. It uses two-dimensional rows and columns to store data. The tables of records can be connected by common key values.

Advantages of using a relational database structure • Reduction of data redundancy, which not Advantages of using a relational database structure • Reduction of data redundancy, which not only reduces the required disk storage space, but also speeds processing. • Flexibility. If data changes, you can update the value in only one place. All queries, forms, and reports look in that place for the current values. • Simplicity. The flat-file model used as the basis for a relational system dictates a simple, non-redundant method of data storage. Each table in the relational design is a single object containing data relevant to a particular aspect of the database, such as an employee, a product, or an order. • Power. Storing the data in separate related tables allows grouping, searching, and retrieving the information in almost unlimited ways. • Ease of management. With smaller, less-complicated tables, the information is much easier to locate and manage.

MS Access is a relational database. Tables are the fundamental objects at the heart MS Access is a relational database. Tables are the fundamental objects at the heart of a relational database. They form the active basis for the information storage and retrieval system. Once the information is arranged in separate tables, you can view, add, edit and delete information with online forms, search for and retrieve some of or all the information with queries; and print information as customized reports. In Access the term database is more precisely used to define the collection of objects that store, track, manipulate, and retrieve data.

Differences between Access и Excel in storing data 1. Working with Excel you enter Differences between Access и Excel in storing data 1. Working with Excel you enter any information in a cell such as a text, a table a figure. So, in one column there may be data of different types – numbers, texts, dates, if necessary. Access table differs from Excel spreadsheet: you can’t have data of different types in one column. 2. Access allows not only enter data in tables but also control them by setting specific rules at the table level. So, it won’t let you save data that don’t meet required rules.

3. Excel is convenient to work with if a table contains a limited number 3. Excel is convenient to work with if a table contains a limited number of rows. Database tables may contain a huge number of records – 7000000. Max size is up to 2 Gb. Database management system offers effective tools to retrieve necessary information. максимальное количество записей 7 000, максимальный размер до 2 Гб 4. If you store all necessary information in Word documents and Excel spreadsheets, then while accumulating it you can meet the problem of dealing with a great number of files. Access allows you to store all data in one file and have access to the page by page, that is not exceeding limitations on computer resources.

5. Access allows to relate tables and, therefore, use data from different tables. For 5. Access allows to relate tables and, therefore, use data from different tables. For users it will be the same as working with one table. Implementing this mode in Excel is very complicated, sometimes impossible. 6. Setting relations with different tables Access allows to avoid duplicate data, save computer memory and increase speed and accuracy of processing.

7. Excel allows for several users to work with one and the same spreadsheet, 7. Excel allows for several users to work with one and the same spreadsheet, but this possibility is limited. Access may support simultaneous work of up to 50 users guaranteeing that each of them will work with actual data. 8. Access has a well-developed system protecting from unauthorized access. If offers tools that allow a user or a group of users to see and change only “their” objects. Excel allows to protect data setting passwords but this tool is significantly less complex.

Types of Relationships Tables can be related in three different ways: – – – Types of Relationships Tables can be related in three different ways: – – – one-to-one, one-to-many, and many-to-many. The type you define depends on how many records in each table are likely to have the same value. To relate tables, one of them must include a field that contains a unique value in every record. This can be a primary key field or a field with a unique index that allows no duplicate values. A primary key or a unique index can also be a combination of two or more fields whose combined value is unique for all records. For example, the Employee ID can be a unique number that identifies an employee. If you want to use names in a key or index, you’d probably need to include both the first and last names to ensure unique values.

One-to-One One-to-One

One-to-One Relationship examples One-to-One Relationship examples

The most commonly used type of relationship is the one-to-many relationship, in which one The most commonly used type of relationship is the one-to-many relationship, in which one record in one table can have one or many matching records in another table, or maybe none at all. The table on “one” side is often called the parent table and the other is called the child table.

One-to-Many Relationship One-to-Many Relationship

One-to-Many Relationships One-to-Many Relationships

More examples More examples

Many-to-Many Relationship Name Marta Smith Phone_number 1234567 9876543 Steven Law 3153759 8642642 Many-to-Many Relationship Name Marta Smith Phone_number 1234567 9876543 Steven Law 3153759 8642642

In Access the most commonly used type of relationship is the one-to-many relationship, in In Access the most commonly used type of relationship is the one-to-many relationship, in which one record in one table can have one or many matching records in another table, or maybe none at all. The table on “one” side is often called the parent table and the other is called the child table. The one-to-one relationship is sometimes used as a form of lookup, in which each record in one of the tables has a matching record in the other table. Neither table is designated as the parent. The key fields in both tables are the primary keys. One use of this type of relationship is to store additional, seldom-accessed information about an item in the first table, such as an abstract of a book or the details of a work order.

[ The many-to-many relationship is not permitted as such in a relational database. Many [ The many-to-many relationship is not permitted as such in a relational database. Many records in one table have the same values in the key field as many records in the second table. To implement this in Access before 2007, you must create a third table, called a junction table, to place between the first two, converting the many-to-many to two one-to-many relationships. Office Access 2007 introduces a new field type, the multivalued field, that can replace the need for the junction table when creating a many-to-many relationship. ]

Referential Integrity (ссылочная целостность данных) Referential integrity is an optional system of rules that Referential Integrity (ссылочная целостность данных) Referential integrity is an optional system of rules that guarantees the relationships are valid and the database will remain intact as data is entered, edited, or deleted. The basic rule of referential integrity is this: For every record in a child table (the “many” side), one and only one matching record must be in the parent table (the “one” side).