AWS Redshift Correlated Subquery and its Restrictions
Redshift Correlated subquery is a query within a query that refer the columns from the parent or outer query. This kind of subquery contains one or more correlations between its columns and the columns produced by the outer query. Redshift does support the regular and correlated subqueries. In most cases, the Redshift correlated subqueries are used to improve the SQL query performance. Page Contents Introduction to Redshift Correlated Subquery What is Redshift Correlated Subquery? Examples of Redshift Correlated Subquery Redshift Correlated Subquery Performance Considerations Redshift Correlated Subquery Restrictions Conclusion Introduction…