Words starting with databasetran
Maybe these words will be useful:
- database administrator — (job) A person responsible for the design and management of one or more databases and for the evaluation, selection and implementation of database management systems. In smaller organisations, the data administrator and database administrator are often one in the same; however, when they are different, the database administrator's function is more technical. The database administrator would implement the database software that meets the requirements outlined by the organisation's data administrator and systems analysts. Tasks might include controling an organisation's data resources, using data dictionary software to ensure data integrity and security, recovering corrupted data and eliminating data redundancy and uses tuning tools to improve database performance.
- database analyst — (job) A person who uses data modeling to analyse and specify data use within an application area. A database analyst defines both logical views and physical data structures. In a client/server environment, he defines the database part of the back end system.
- database machine — (hardware) A computer or special hardware that stores and retrieves data from a database. It is specially designed for database access and is coupled to the main (front-end) computer(s) by a high-speed channel. This contrasts with a database server, which is a computer in a local area network that holds a database. The database machine is tightly coupled to the main CPU, whereas the database server is loosely coupled via the network.
- database normalisation — (database) A series of steps followed to obtain a database design that allows for efficient access and storage of data in a relational database. These steps reduce data redundancy and the chances of data becoming inconsistent. A table in a relational database is said to be in normal form if it satisfies certain constraints. Codd's original work defined three such forms but there are now five generally accepted steps of normalisation. The output of the first step is called First Normal Form (1NF), the output of the second step is Second Normal Form (2NF), etc. First Normal Form eliminates repeating groups by putting each value of a multi-valued attribute into a new row. Second Normal Form eliminates functional dependencies on a partial key by putting the fields in a separate table from those that are dependent on the whole key. Third Normal Form eliminates functional dependencies on non-key fields by putting them in a separate table. At this stage, all non-key fields are dependent on the key, the whole key and nothing but the key. Fourth Normal Form separates independent multi-valued facts stored in one table into separate tables. Fifth Normal Form breaks out data redundancy that is not covered by any of the previous normal forms.
- database query language — (database) A language in which users of a database can (interactively) formulate requests and generate reports. The best known is SQL.
- database server — A stand-alone computer in a local area network that holds and manages the database. It implies that database management functions, such as locating the actual record being requested, is performed in the server computer. Contrast with file server, which acts as a remote disk drive and requires that large parts of the database, for example, entire indexes, be transmitted to the user's computer where the real database management tasks are performed. First-generation personal computer database software was not designed for a network; thus, modified versions of the software released by the vendors employed the file server concept. Second-generation products, designed for local area networks, perform the management tasks in the server where they should be done, and consequently are turning the file server into a database server.
- database transaction — (database) A set of related changes applied to a database. The term typically implies that either all of the changes should be applied or, in the event of an error, none of them, i.e. the transaction should be atomic. Atomicity is one of the ACID properties a transaction can have, another is isolation - preventing interference between processes trying to access the database cocurrently. This is usually achieved by some form of locking - where one process takes exclusive control of a database table or row for the duration of the transaction, preventing other processes from accessing the locked data. The canonical example of a transaction is transferring money between two bank accounts by subtracting it from one and adding it to the other. Some relational database management systems require the user to explicitly start a transaction and then either commit it (if all the individual steps are successful) or roll it back (if there are any errors).
- database — A database is a collection of data that is stored in a computer and that can easily be used and added to.
- database management — the maintenance of information stored in a computer system
- database management system — a suite of computer programs that together provide the necessary functions for database management