0
Database Design
Database design is the process of creating a detailed data model of a database. It is the next step after requirement gathering and before coding begins. A good database design can save a lot of time during the database development.
1,295 Questions
A relational model is the means of ordering elements that relates to one another, called a tuple.
Multiple tuples of similar structure can be seen as a table, with rows that describe each tuple, and similar elements ordered in columns.
All operation are described as binary operation as in calculus, e.g. "Insert" is the same as addition, as a new relation is added, where the elements in the relation constitutes a new unique group of values.
Any tuple can have a relation to another tuple - such as "they belong together" or "one comes after the other".
That relations can be represented as tables is used by a number of application building tools, such as MS Access. These refer to the similar elements - the column by assigning them names. They will usually also assume a similar datatype (int, numeric text, float, code, text, etc). The relation model is entirely based on mathematics, relational calculus and relational algebra developed by Chris Data and Ted Codd at Watson Height, IBM Research Center.
The relational model does not relate to any relationship between the tables, and relationships needs to be coded by the application programmer that use codes to make e.g. a parent relates to child. The database system can implement constraints such as that every child has a parent, while not every person has a child.
The model is then used by application developers to create the user interface.
The competing model is the CODASYL network model that was made to satisfy the requirements for application support. This will provide "pointers" that can link a child to a parent, and an order line to a order. However, these does not lend themselves to allow generic tools such MS Access to make the applications, as it does not support the flexibility needed to "just make it".
What is centralized decision making?
Centralized decision making is whereby a top manager retain most decision- making power to him/her self.
How is security implemented in a relational database?
Security is one of the key concern of a database administrator. Security can be added to the user, object etc. An object (table,views,stored procedures etc) can have multiple permissions. A database administrator can grant revoke permissions to the objects. Security is implemented based on the data sensitiveness also. If there is a table for password, make sure that only it's encrypted and can be accessible through administrator only.
A WORM drive is a type of CD writer. WORM is short for "Write Once, Read Many." So that just means it can write to CD-R (recordable) discs once, and that the resulting CDs can be used quite a few times (until scratched up or exposed to lots of UV light). That is different from CD-RW (rewritable) which means it can be written to a few times or so and read many times.
Another thing called a worm is similar to a virus but spreads over a network. If you have one in your computer, you would need an antivirus or other malware removal software to remove it. A worm can be used to launch denial of service attacks against other machines. The worm may take orders from an IRC channel and many infected machines could be told to attack a certain IP address and prevent it from using the Internet.
What is the Difference between an architect and a dba?
An architect is someone who designs the business rules and physical layout of the database. A DBA maintains the database environment, and depending on the extent of the DBA's skills also does the database programming. In doing so executes the architects vision.
How do you create a login page with user name and password fields?
It is quite simple to create a login page, it is simply a form input, if all the people hold the same username and password. If you want and I suspect you do, a unique service, then you will need to install a database. I have no experience of this.
What are the advantages of direct conversion?
The advantage of this strategy is that it requires no transition costs and is a quick.
When creating a table every field in Access must have what two things associated with it?
Every field must have a name. They also must have a data type. For some field types, you also need to have a size, though a default size will be set for those fields.
Your library is corrupt.
What is data quality specialist?
We specialise in recovering data from a variety of devices capable of storing user's data. We offer the most comprehensive Data recovery service in the UK.Plymouth Data Recovery specialises in recovering data from a wide range of devices capable of storing data. We recover data from PCs, External HDDs, Laptops, RAID setups and a whole host of removable storage devices. We have 15+ years experience in the field of data recovery and carry out 1000s of recoveries annually.
http://www.plymouthdatarecovery.co.uk/
Relationship between CAD and CAM?
The relationship between CAD (Computer aided design) and CAM (computer aided manufacturing) is that both types of designing need to be done on a computer and operated by an engineer.
Give the Name of 10 situations that can be represented by means of graphs?
Financial history Score history Statistical analysis data set averages data set trends time value of money usage statistics performance statistics personal achievement trends grade history and analysis time vs. productivity models
RDBMS is short for Relational database management system . RDBMS defines relationship between the tables . MPP stands for massive parallel processing and in RDBMS MPP refers to the processing of several table ,that are in relation with one another together.
What is Procedural query language?
A procedural language is nothing but what we call relational algebra. Procedural language is just like SQL but with different syntax. In Procedural language for "Select" we use projection and for "where" clause we use selection.
What is the importance of setting criteria in Ms Access queries?
Basically a "query" is a way of asking the database a question, i.e.
How many people,
have a red car.
The query is set an can be a one off question or can be a question it is asked regularly.
The criteria is in effect the question you want answered i.e. how many people in you database have a red car So in the data base you may have the name, address, car type, car colour. In the colour field you would set the criteria as RED. Then running the query you will get all the cars that are red. If you then placed in the field on the database data about the type of car this could be Sports, saloon, hatchback SUV
So you can then ask red in the colour filed of the query and SUV for example in the TYPE field. It is the queries that make the database do its job of reporting back the information.
Your reservation is confirmed. We are looking forward to seeing you.
