Index - Index , .Eachindexis

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Index An index is a database object that provides direct access to rows in a table.  Once an index has been created, Oracle will use it whenever possible to  speed up the access to data. An index structure is independent from the table structure. Each index is  composed of column values that the index is on and pointers to the row  containing the value. Syntax CREATE INDEX indexName ON table (column 1, …); EXAMPLE 1 Create the departments table: Drop table departments cascade constraints; create table departments (        departmentid number primary key,        departmentName varchar (15) ); Create the employees table with the foreign key referencing departments: drop table employees cascade constraints; create table employees
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(         id integer PRIMARY KEY,         fname varchar (10),         lname varchar (15),         title varchar (15),
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This note was uploaded on 12/22/2009 for the course DBST DBST 651 taught by Professor Yelena - ta during the Spring '09 term at MD University College.

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Index - Index , .Eachindexis

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