The I/O Activity tab on the Tablespace Analysis drilldown provides a summary of I/O activity on the selected tablespace. The graphs show rates for the following:
Reads and writes that use the buffer pool
Direct reads and writes, which do not go through the buffer pool, but access the tablespace directly
The bottom of the drilldown lists average I/O times (in milliseconds) for both buffered and direct reads and writes. The average times are shown in milliseconds.
On the Database Analysis drilldown, you might notice consistently high rates for the following activities on specific databases:
Physical read rates (compared to logical read rates)
Synchronous read or write rates
Direct I/O rates for a database
These high rates might be indications of performance degradation since the activities involve disk I/O and slow-downs in query processing. Use the graphs listed above to pinpoint those tablespaces on which the high I/O activity is occurring.
The following graphs on the I/O Activity tab keep track of the rates for I/O activity on the selected tablespace. These rates are plotted over consecutive monitoring intervals.