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Primary Key - Default Indexes of Tables in SQL Server
Is the PRIMARY KEY Column of a Table an Index in SQL Server?
✍: FYIcenter.com
If you define a primary key on a table, an index for the primary key column will be created by default. The tutorial exercise below shows you the index created as part of the primary key column of "fyi_links":
USE FyiCenterData; GO -- Drop the old table, if needed DROP TABLE fyi_links; GO -- Create a table with primary key CREATE TABLE fyi_links ( id INT PRIMARY KEY, url VARCHAR(80) NOT NULL, notes VARCHAR(1024), counts INT, created DATETIME NOT NULL DEFAULT(getdate()) ); GO -- Create an index for column "url" CREATE INDEX fyi_links_url ON fyi_links (url); GO -- View indexes EXEC SP_HELP fyi_links; GO index_name index_description keys ----------------------- -------------------------- ---- fyi_links_url nonclustered located url on PRIMARY PK__fyi_links__239E4DCF clustered, unique, primary key located on PRIMARY id
Notice that the index created as part of the primary key is named by SQL Server as "PK__fyi_links__239E4DCF".
⇒ UNIQUE Constraint Creating Default Index in SQL Server
⇐ DROP INDEX - Removing Existing Indexes in SQL Server
2016-11-13, 1354🔥, 0💬
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