sqlperformancecountstatisticsdatabase-scan

sql statistics io scan count explanation


Simple question, but I haven't found a good explanation on google. When using Set Statistics IO ON, the logical reads and scan count is provided in the message window of management studio. If I have:

tblExample, scan count 5, logical reads 20

What does scan count signify?


Solution

  • From Books On Line

    Scan count: Number of index or table scans performed.

    logical reads: Number of pages read from the data cache.

    physical reads: Number of pages read from disk.

    read-ahead reads: Number of pages placed into the cache for the query.

    See also here: http://technet.microsoft.com/en-us/library/ms184361.aspx