Amazon Redshift data sharing allows you to share live, transactionally consistent data across different Redshift clusters without the complexity and delays associated with data copies and data movement. Ability to share data across clusters that are in the same AWS account is already available. Now sharing data across Redshift clusters in different AWS accounts is also generally available. Cross-account data sharing is supported on all Redshift RA3 node types. There is no additional cost to use cross-account sharing on your Amazon Redshift clusters.
Source:: Amazon AWS