Field

Description

Buffer Pools

Number

Number of buffer pools

Total Size

Total size in KB of all buffer pools

Buffer Quality

Overall Buffer Quality

Indicates percentage at which the data is read from the buffer pool, rather than directly from the hard disk.
This is calculated using the following formula:
(logical reads - physical reads) / (logical reads) * 100

Data Hit Ratio

Indicates percentage at which data (without index data) is read from the buffer pool, rather than directly from the hard disk

Index Hit Ratio

Indicates the frequency as a percentage at which index data is read from the buffer pool, rather than directly from the hard disk

Average Time

Physical Reads

Average time in milliseconds required to read data from disk into the buffer pool

Physical  Writes

Average time in milliseconds required to write data from the buffer pool to disk

Data

Logical Reads

Number of read accesses to data in the buffer pool

Physical Reads

Number of read accesses to data on disk (I/O). The value includes the number of physical reads that were performed synchronously (by the database manager agents) and asynchronously (by the I/O servers).

Physical Writes

Number of write accesses to data on disk (I/O). The value includes the number of physical writes that were performed synchronously (by the database manager agents) and asynchronously (by the I/O cleaners).

Synchronous Reads

Number of read accesses to data on disk (by agents)

Synchronous Writes

Number of write accesses to data on disk (by agents)

Temporary Logical Reads

Number of logical read requests that required I/O to get data pages into the temporary tablespace

Temporary Physical Reads

Number of physical read requests that required I/O to get data pages into the temporary tablespace

Index

Logical Reads

Number of read accesses to index data in the buffer pool

Physical Reads

Number of read accesses to index data on disk (I/O). Since index data is read only by the database manager agents, this value includes the number of synchronously read index pages.

Physical Writes

Number of write accesses to index data on disk (I/O). The value includes the number of physical writes that were performed synchronously (by the database manager agents) and asynchronously (by the I/O cleaners).

Synchronous Reads

Number of read accesses to index data on disk (by agents)

Synchronous Writes

Number of write accesses to index data on disk (by agents)

Temporary Logical Reads

Number of logical read requests that required I/O to get index pages into the temporary tablespace

Temporary Physical Reads

Number of physical read requests that required I/O to get index pages into the temporary tablespace