What is Cartesian product in SQL?

Question

Could someone tell me what is a Cartesian product in SQL?

Answer 1

The Cartesian product in SQL is the result of combining every row from one table with every row from another table. It occurs when no join condition is specified in the SQL query, resulting in a cross join between the tables. The resulting Cartesian product contains the total number of rows from the first table multiplied by the total number of rows from the second table. It can be useful for generating all possible combinations or finding the union of two tables without any common column. However, it can lead to large result sets, impacting performance. To limit the Cartesian product, a WHERE clause or join condition can be used.

Answer 2

Cartesian Product or Cross Join is a type of join used in SQL. This type of join is done by making every row of a table with every other join in the other table, and thus returns the Cartesian product of the sets of records from two or more joined tables. If you are interested in learning SQL and wish to master it, then check out the SQL certification course from Intellipaat. Also, watch the following video on SQL Interview Questions and Answers that are made by industry experts.

Answer 3

The Cartesian product in SQL refers to the result obtained by combining every row from one table with every row from another table.

It is obtained when no join condition is specified in the SQL query, resulting in a cross join between the tables.

The resulting Cartesian product contains the total number of rows from the first table multiplied by the total number of rows from the second table.

For example, if Table A has 5 rows and Table B has 3 rows, the Cartesian product between the two tables would result in 5 x 3 = 15 rows.

The Cartesian product can be useful in certain scenarios, such as generating all possible combinations between two tables or when you want to find the union of two tables without any common column.

However, it can also lead to large result sets, which can negatively impact performance and consume significant resources.

To limit the Cartesian product, you can use a WHERE clause or join condition to specify the relationship between the tables or apply additional filtering criteria.

Answer 4

Cartesian product in SQL combines every row from one table with every row from another table, resulting in a cross join.