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SQL Cartesian Product

I will explain SQL Cartesian Product in this post.

 

SQL Cartesian Product

 

SQL Cartesian Product is used when any join conditions don’t exist between tables. Cartesian product is created between two data sources, and Optimizer joins every row from one source with every row from the other data source as follows.

 

 

 

 

 

CARTESIAN PRODUCT

 

For example; hr.regions and hr.locations will be used in the cartesian product as follows.

 

SELECT COUNT(*) FROM hr.regions ;             SELECT COUNT(*) FROM hr.locations ;

                                                                                

 

SELECT * FROM hr.regions, hr.locations;

 

HR.REGIONS has 4 row and HR.LOCATIONS has 23 rows, when you did the cartesian product between these two tables, result will be 4×23 = 92 rows like above.

 

 

 

 

 

 

Do you want to learn Oracle SQL for Beginners, then read the following articles.

Oracle SQL Tutorials For Beginners – Learn Oracle SQL from scratch with Oracle SQL Online Course

 

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