Difference Between NOT IN vs NOT EXISTS Operator

Setting Up Environment

Let us start by creating a sample table and inserting some values into it. For this article, we are going to create an employee table that contains information on the manager of each employee. We will later use this manager information to understand NOT IN and NOT EXISTS clauses. The following query creates the specified table and inserts some rows into it....

Example of NOT IN vs NOT EXISTS in PostgreSQL

Example of NOT IN Operator...

Difference Between NOT IN vs NOT EXISTS Operator

The following are some of the differences between NOT IN and NOT EXISTS:...

Conclusion

Overall, After reading whole article both NOT IN and NOT EXISTS are used for solving subquery results in PostgreSQL, they have distinct characteristics. NOT EXISTS is typically more efficient, especially for large datasets, due to its ability to terminate processing once a match is found and NOT IN can lead to unexpected results if the subquery contains NULL values We have seen in the above examples that the in NOT EXISTS we don’t need to specify to contain NOT NULL value but in NOT IN we have to specify that to contain NOT NULL values....