In the Student Clubs database design, the design team worked to achieve these objectives. For example, to track memberships, a simple solution might have been to create a members field in the Clubs table and then just list the names of all of the members there. . However, this design would mean that if a student joined two clubs, then his or her information would have to be entered a second time. Instead, the designers solved this problem by using two tables: Students and Memberships. In this design, when a student joins their first club, we first must add the student to the Students table, where their first name, last name, e-mail address, and birth year are entered. This addition to the Students table will generate a student. Now we will add a new entry to denote that the student is a member of a specific club. This is accomplished by adding a record with the student id and the club id in the memberships table.
Tuning the db2 on z/OS
A students e-mail address might be a good choice for a primary key, since e-mail addresses are unique. However, a primary key cannot change, so this would mean that if students changed their e-mail address we would have to remove them from the database and then re-insert them not an attractive proposition. . Our solution is to create a value for each student — a user id — that will act as a primary key. We will also do this for each of the student clubs. This solution is quite common and is the reason you have so many user IDs! You can see the final database design in the figure below: Student Clubs database diagram, with this design, not only do we have a way to organize all of the information we need to meet the requirements, but we have also successfully related all the. Heres what the database tables might look like with some sample data. Note that the memberships table has the sole purpose of allowing us to relate multiple students to multiple clubs. When designing a database, one important concept to understand is normalization. In simple terms, to normalize a database means to design it in a way that: 1) reduces duplication of data between tables and 2) gives the table as much flexibility as possible.village
For example, club Name would where be one of the fields in the Clubs table. First Name and Last Name would be fields in the Students table. Finally, since this will be a relational database, every table should have a field in common with at least one other table (in other words: they should have a relationship with each other). In order to properly create this relationship, a primary key must be selected for each table. This key is a unique identifier for each record in the table. . For example, in the Students table, it might be possible to use students last name as a way to uniquely identify them. However, it is more than likely that some students will share a last name (like rodriguez, smith, or lee so a different field should be selected.
From this, the team decides that the system must keep track of the clubs, their members, and their events. Using this information, the design team determines that the following tables need to be created: Clubs: this will track the club name, the club president, and a short description of the club. Students: student name, e-mail, and year of birth. Memberships: this table will correlate students with clubs, allowing us to have any given student join multiple clubs. Events: this table will track when the clubs meet and how many students showed. Now that the design team has determined which umum tables to create, they need to define the specific information that each table will hold. . This requires identifying the fields that will be in each table.
In a relational database, all the tables are related by one or more fields, so that it is possible to connect all the tables in the database through the field(s) they have in common. For each table, one of the fields is identified as a primary key. This key is the unique identifier for each record in the table. . To help you understand these terms further, lets walk through the process of designing a database. Designing a database, suppose a university wants to create an information system to track participation in student clubs. After interviewing several people, the design team learns that the goal of implementing the system is to give better insight into how the university funds clubs. This will be accomplished by tracking how many members each club has and how active the clubs are.
Data, collection and, warehouse, feature
It is an organized collection, because in a database, all data is described and associated with other data. All information in a database should be related as well; separate databases should be created to manage unrelated information. For example, a database that contains information about students should not also hold information about company stock prices. . Databases are not always digital a filing cabinet, for instance, might be considered a form of database. For the purposes of this text, we will only consider digital databases. Relational Databases, databases can be organized in many different ways, and thus take many forms. The most popular form of database today is the relational database.
Popular examples of relational databases are microsoft Access, mysql, and Oracle. A relational database is one in which data is organized into one or more tables. Each table has a set august of fields, which define the nature of the data stored in the table. A record is one instance of a set of fields in a table. . to visualize this, think of the records as the rows of the table and the fields as the columns of the table. In the example below, we have a table of student information, with each row representing a student and each column representing one piece of information about the student. Rows and columns in a table.
The final step up the information ladder is the step from knowledge (knowing a lot about a topic) to wisdom. We can say that someone has wisdom when they can combine their knowledge and experience to produce a deeper understanding of a topic. It often takes many years to develop wisdom on a particular topic, and requires patience. Almost all software programs require data to do anything useful. For example, if you are editing a document in a word processor such as Microsoft Word, the document you are working on is the data.
The word-processing software can manipulate the data: create a new document, duplicate a document, or modify a document. Some other examples of data are: an MP3 music file, a video file, a spreadsheet, a web page, and an e-book. In some cases, such as with an e-book, you may only have the ability to read the data. The goal of many information systems is to transform data into information in order to generate knowledge that can be used for decision making. In order to do this, the system must be able to take data, put the data into context, and provide tools for aggregation and analysis. . A database is designed for just such a purpose. A database is an organized collection of related information.
Logical Design in, data, warehouses
Ruby red, the color of a 2013 Ford Focus, is an example of qualitative data. . A number rainbow can be qualitative too: if I tell you my favorite number is 5, that is qualitative data because it is descriptive, not the result of a measurement or mathematical calculation. By itself, data is not that useful. To be useful, it needs to be given context. Returning to the example above, if I told you that 15, 23, 14, and letter 85 are the numbers of students that had registered for upcoming classes, that would be information. By adding the context that the numbers represent the count of students registering for specific classes i have converted data into information. Once we have put our data into context, aggregated and analyzed it, we can use it to make decisions for our organization. We can say that this consumption of information produces knowledge. This knowledge can be used to make decisions, set policies, and even spark innovation.
Without data, hardware and software are not very useful! . Data is the third component of an spring information system. Data are the raw bits and pieces of information with no context. If I told you, 15, 23, 14, 85, you would not have learned anything. But I would have given you data. Data can be quantitative or qualitative. Quantitative data is numeric, the result of a measurement, count, or some other mathematical calculation. Qualitative data is descriptive. .
knowledge; define the term database and identify the steps to creating one; describe the role of a database management system; describe the characteristics of a data warehouse;. You have already been introduced to the first two components of information systems: hardware and software. However, those two components by themselves do not make a computer useful. Imagine if you turned on a computer, started the word processor, but could not save a document. Imagine if you opened a music player but there was no music to play. Imagine opening a web browser but there were no web pages.
For tables containing cross tabulations an additional file is provided with the data is provided in one row per geography to aid with its use as requested by users of bulk data. NB: The 2011 Census thesis Index (takes you to the nrs website) provides a lookup for users to access and cross-match textual descriptions of each geography against the unique s numbers. . For more information, please contact. If a table you want isn't available you can submit a request; visit the. Commissioned Outputs page for more information. For all information on amendments that have been made to the downloadable data, please visit the. Revisions and Corrections page.
Project Risk Assessment Reporting
What is the data warehouse? The data warehouse provides options for downloading large volumes of Scotlands Census 2011 data. . to find out what. Standard Output, additional tables and, commissioned outputs are available for download please use the. Scotland's Census Tables Index (Excel, 324KB) to find out what 'standard 'additional' and 'commissioned' tables have been published. Please note disadvantages this search tool is currently not compatible with Mac os x, an index only version is available here (Excel, 710kb two options are provided for downloading the. Standard Output tables: the standard data files " effectively replicate the format of the tables as provided through the Standard Outputs section of the website and offers the tables in csv format with textual descriptions of each geography (e.g Aberdeen City) the bulk data files.