MS-SQL Support
Mainstream Support
At the supported service pack level, Mainstream Support includes:
Incident support (no-charge incident support, paid incident support, and support charged on an hourly basis)
Security update support
The ability to request non-security hotfixes through CSS or the Product Team
https://sqlserverperformance.wordpress.com/2011/01/30/microsoft-support-policies-for-windows-server-and-sql-server/
Extended Support
At the supported service pack level, Extended Support includes:
Paid support
Security update support at no additional cost
Non-security related hotfix support requires a separate Extended Hotfix Support Agreement to be purchased (per-fix fees also apply)
https://sqlserverperformance.wordpress.com/2011/01/30/microsoft-support-policies-for-windows-server-and-sql-server/
Extended Security Updates
For SQL2008/2008R2 in Azure, this is free! (if you have Software Assurance).
Customers with active Software Assurance or subscription licenses can purchase Extended Security Updates for approximately 75% of the on-premises license cost annually. (1)
For SQL2008/2008R2 this is available for three years after end of Extended Support (ending 12-Jul-2022)
Premium Assurance
This no longer be available. Replaced by Extended Security Updates.
Extends Support for a further 6 years
Only available if you have Software Assurance
https://www.computerworld.com/article/3148768/for-a-price-microsoft-will-extend-support-for-windows-server-sql-server-6-more-years.html
Bibliography
https://docs.microsoft.com/en-US/lifecycle/policies/fixedhttps://learn.microsoft.com/en-us/lifecycle/policies/fixedhttps://learn.microsoft.com/en-us/troubleshoot/sql/general/support-policy-sql-server (Technical support policy for Microsoft SQL Server)https://learn.microsoft.com/en-us/sql/sql-server/end-of-support/sql-server-end-of-support-overviewhttps://learn.microsoft.com/en-us/sql/sql-server/end-of-support/sql-server-extended-security-updateshttps://support.microsoft.com/en-us/help/4456242/end-of-support-for-sql-server-2008-and-sql-server-2008-r2(1) https://www.microsoft.com/en-us/windows-server/extended-security-updateshttps://docs.microsoft.com/en-US/lifecycle/faq/extended-security-updateshttps://www.microsoft.com/en-us/windows-server/extended-security-updates