| November 11, 2008 03:40:05 |
#2 |
| srimanta.mandal |
Member Since: November 2008 Total Comments: 1 |
RE: How do we maintain Primary key in Fact Table ?
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In data warehousing we are used surrogate keys by which we can change the value of primary key.
Suppose you have two table emp and dept, and empno is the primary key of dept. table and also it is used in emp table as fk. In this case if we cannot modify the pk.
because it is used as a foreign key in dept table. Thats why we need a extra colums which have no actual meaning.
Here we have to take a extra columns ID as surrogate key in both table which have no meaning.
But it can perform the joins between two tables. |
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