Первичный ключ

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SHD_ (2006-05-26 16:17) [0]

Кто нить знает в MSSQL первичный ключ является индексом или нет?

В общем создавать индекс на первичный ключ нужно?

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Desdechado © (2006-05-26 16:19) [1]

ключ индексом не является, но требует уникального индекса для проверки "ключевости"
это обычно
как в MS - хз

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Zz_ (2006-05-26 16:20) [2]

When you specify a PRIMARY KEY constraint for a table, Microsoft® SQL Server™ 2000 enforces data uniqueness by creating a unique index for the primary key columns. This index also permits fast access to data when the primary key is used in queries.

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Ega23 © (2006-05-26 17:03) [3]

PRIMARY KEY Constraints A table usually has a column or combination of columns whose values uniquely identify each row in the table. This column (or columns) is called the primary key of the table and enforces the entity integrity of the table. You can create a primary key by defining a PRIMARY KEY constraint when you create or alter a table. A table can have only one PRIMARY KEY constraint, and a column that participates in the PRIMARY KEY constraint cannot accept null values. Because PRIMARY KEY constraints ensure unique data, they are often defined for identity column. When you specify a PRIMARY KEY constraint for a table, Microsoft® SQL Server™ 2000 enforces data uniqueness by creating a unique index for the primary key columns. This index also permits fast access to data when the primary key is used in queries. If a PRIMARY KEY constraint is defined on more than one column, values may be duplicated within one column, but each combination of values from all the columns in the PRIMARY KEY constraint definition must be unique.

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