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

P

A lock that covers 8KB of data.

partitioned view

A table that has been replaced with multiple, smaller tables. Each smaller table has the same format as the original table, but with a subset of the data. Each partitioned table has rows allocated to it based on some characteristic of the data, such as specific key ranges. The rules that define into which table the rows go must be unambiguous. For example, a table is partitioned into two tables. All rows with Primary Key values lower than a specified value are allocated to one table, and all rows equal to or greater than the value are allocated to the other. Partitioning can improve application processing speeds and reduce the potential for conflicts in multi-site update replication. You can improve the usability of partitioned tables by creating a view. The view, created by a union of select operations on all the partitioned tables, presents the data as if it all resided in a single table.

performance monitor

The NT implementation of system monitor.

Primary Key

A column or set of columns that uniquely identify all the rows in a table. Primary Keys do not allow null values. No two rows can have the same Primary Key value; therefore, a Primary Key value always uniquely identifies a single row. More than one key can uniquely identify rows in a table; each of these keys is called a candidate key. Only one candidate can be chosen as the Primary Key of a table; all other candidate keys are known as alternate keys. Although tables are not required to have Primary Keys, it is good practice to define them. In a normalized table, all the data values in each row are fully dependent on the Primary Key. For example, in a normalized employee table that has EmployeeID as the Primary Key, all the columns should contain data related to a specific employee. This table does not have the column DepartmentName because the name of the department is dependent on a department ID, not on an employee ID.

Profiler

SQL Profiler is a tool that captures SQL Server 2000 events from a server. The events are saved in a trace file that can later be analyzed or used to replay a specific series of steps when you want to diagnose a problem.

publication

A container for articles that is capable of being replicated. A publication, which may include one or more articles, is the basic unit of replication. A publication has a single, specific replication type: either snapshot, transactional, or merge. When a subscriber chooses a publication, all the articles contained within the publication are part of the subscription.

Publisher

In respect with replication, the Publisher is the server that produces data so that it can be replicated to Subscribers.