I was looking at the SQL Server 2017 Documentation for page and extent allocations.
What I got to know from online resources and sessions in SQL conferences: Starting with SQL Server 2016, Uniform Extent Allocation is the default behavior. However, what MS documentation describes is:
To make its space allocation efficient, SQL Server does not allocate whole extents to tables with small amounts of data.
- Uniform extents are owned by a single object; all eight pages in the extent can only be used by the owning object.
- Mixed extents are shared by up to eight objects. Each of the eight pages in the extent can be owned by a different object.
A new table or index is generally allocated pages from mixed extents. When the table or index grows to the point that it has eight pages, it then switches to use uniform extents for subsequent allocations
So, my question is: In SQL server 2016 and later, if we create a new table or index, will it be allocated a uniform extent or a mixed extent initially?