Statistics for reads

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 4-1 shows the values that statistics io reports for logical and physical reads.

**Table 4-1: statistics io output for 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.