The space available property is not computed correctly

The Database.SpaceAvailable property is not computed correctly. The reason for this issue is that the input used in the calculation of this property, as seen in the source code, relies on a join operation between the sys.allocation_units and sys.partitions DMVs. However, this inner join is incompatible with columnstore indexes, as clearly documented in the official documentation. Consequently, the size is inaccurately computed for databases using columnstores. The solution is straightforward: remove this incompatible join operation from the calculation.

src/Microsoft/SqlServer/Management/SqlEnum/PostProcessDatabaseInsideAttribs.cs の Database.SpaceAvailable に関するリンク先の計算から始めます。sys.allocation_units と sys.partitions がどのように結合されているかを確認し、次に columnstore インデックスを使用するデータベースで結果を検証します。プロパティが互換性のない結合なしで正しい使用可能領域を報告すれば完了です。