EXAM CRAM™ 2 Designing and Implementing Databases with SQL Server 2000 Enterprise Edition [Electronic resources] نسخه متنی

D

A database specifically structured for query and analysis. A data warehouse typically contains data representing the business history of an organization.

database lock

The largest of locking increments affecting the entire database.

DBRE DBREINDEX

A Database Console Command used to rebuild indexes. Out of the different ways of rebuilding an index, the preferred is DBREINDEX because it does not require that you rebuild indexes individually, but it enables you to rebuild multiple indexes in a single shot.

deadlock

A state in which two users or processes cannot continue processing because they each have a resource that the other needs.

DELETE

The DELETE T-SQL statement can be used to delete data from a table. A fast way to delete all rows is TRUNCATE TABLE.

DELETE trigger

DELETE triggers are FOR or AFTER triggers that can restrict data from being deleted from a table, or to perform any other action with the deleted datasuch as logging the deletion or generating an alert. They fire automatically when a DELETE statement is executed against the table.

denormalization

The process of adding planned redundancy to an already fully normalized data model.

derived table

In a FROM clause, you can use a SELECT statement in parentheses as one of the tables you are selecting from. This is called a derived table.

deterministic

A function is deterministic if it always returns the same output when presented with the same input. Mathematical functions, such as SQRT, are deterministic because they always return the same output given the same input.

distributed partitioned view

A distributed partitioned view collects data from two or more instances of SQL Server; a new feature to SQL Server 2000.

distributor

In SQL Server terminology, the Distributor is the server that contains the distribution database, data history, and transactions; as its name implies, its job is to distribute data to Subscribers.

DROP

A command used to drop a database object, such as a view or stored procedure. Using DROP removes all the permissions for the object, as well as the object itself. For example, the DROP VIEW statement is used to remove a view or indexed view from the database. Dropping a view removes the definition of a view from the database and an entry in the sysobjects while not affecting the underlying tables and views.