Collections:
What Are Indexes in SQL Server
What Are Indexes in SQL Server?
✍: FYIcenter.com
An index is a secondary database object associated with a table to improve the retrieval performance of rows from that table.
An index can be defined for a single column or multiple columns of a given table. If an index is defined on a single column of a table, the index can be viewed as ordered map between all values in that column and their row locations in the table. For examples, if you have table with a column called "company_num" and you created an index for that column. The contents of the table and the index may look like what is presented in the following picture:
As shown in the above picture, locating the rows of company_num = 17 can be done much faster through the index.
⇒ CREATE INDEX - Adding an Index on an Existing Table in SQL Server
⇐ Understanding and Managing Indexes in SQL Server
2016-11-15, 3631🔥, 0💬
Popular Posts:
How To Convert Numeric Expression Data Types using the CAST() Function in SQL Server Transact-SQL? I...
Is PL/SQL Language Case Sensitive in Oracle? PL/SQL language is not case sensitive: Reserved words a...
What is test testing area for? The testing area is provided to allow visitors to post testing commen...
What Privilege Is Needed for a User to Delete Rows from Tables in Another Schema in Oracle? For a us...
How To Assign Debug Privileges to a User in Oracle? In order to run SQL Developer in debug mode, the...