statistics io reports the number of logical and physical reads for each table and index included in a query, including worktables. I/O for indexes is included with the I/O for the table.
Table 35-1 shows the values that statistics io reports for logical and physical reads.
Output |
Description |
|
---|---|---|
logical reads |
||
regular |
Number of times that a page needed by the query was found in cache; only pages not brought in by asynchronous prefetch (APF) are counted here. |
|
apf |
Number of times that a request brought in by an APF request was found in cache. |
|
total |
Sum of regular and apf logical reads. |
|
physical reads |
||
regular |
Number of times a buffer was brought into cache by regular asynchronous I/O |
|
apf |
Number of times that a buffer w.as brought into cache by APF. |
|
total |
Sum of regular and apf physical reads. |
|
apf IOs used |
Number of buffers brought in by APF in which one or more pages were used during the query. |