sql server 数字后面的点是什么意思

Question

;WITH DBIO AS ( SELECT DB_NAME(IVFS.database_id) AS db, CASE WHEN MF.type=1 THEN 'log' ELSE 'data' END AS file_type, SUM(IVFS.num_of_bytes_read+IVFS.num_of_bytes_written) AS IO, SUM(IVFS.io_stall) AS io_stall FROM sys.dm_io_virtual_file_stats(null,null) IVFS JOIN sys.master_files AS MF ON IVFS.database_id=MF.database_id AND IVFS.file_id=MF.file_id GROUP BY DB_NAME(IVFS.database_id),MF.type ) SELECT db,file_type, CAST(1.* IO/(1024*1024) AS DECIMAL(12,2)) AS io_mb, CAST(io_stall/1000. AS DECIMAL(12,2)) AS io_stall_s, CAST(100. * io_stall/SUM(io_stall) OVER() AS DECIMAL(10,2)) AS io_stall_pct, ROW_NUMBER() OVER(ORDER BY io_stall DESC) AS rn FROM DBIO ORDER BY io_stall DESC 1. 和 100. 加上点之后什么意思

Answer 1

告诉SQL Server， 别当整数处理，这是小数计算。

Answer 2

表示小数。

Answer 3

表示小数计算。