Natural join projection and cartesian product
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Natural-Join (simpler) is a replacement for Cartesian-Product (lengthy and complex).
In Relational Algebra, there are some fundamental operations such as
1. Select operation (unary)
2. Projection operation (unary)
3. Rename operation (unary)
4. Union (Binary)
5. Set-difference (binary)
6. Cartesian-Product (binary)
These fundamental operations are sufficient to express any query. But the problem is,if we only decide to use fundamental operations, some queries will become complex and lengthy. So, some additional operations are added to simplify queries. Such as:
1. Natural-Join
2. Set-intersection
3. Division
Now, the job of natural join is to simplify the queries which require a Cartesian-Product. So I think we should avoid Cartesian-product and rather use natural join.
In Relational Algebra, there are some fundamental operations such as
1. Select operation (unary)
2. Projection operation (unary)
3. Rename operation (unary)
4. Union (Binary)
5. Set-difference (binary)
6. Cartesian-Product (binary)
These fundamental operations are sufficient to express any query. But the problem is,if we only decide to use fundamental operations, some queries will become complex and lengthy. So, some additional operations are added to simplify queries. Such as:
1. Natural-Join
2. Set-intersection
3. Division
Now, the job of natural join is to simplify the queries which require a Cartesian-Product. So I think we should avoid Cartesian-product and rather use natural join.
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