* Adjust touch count instance parameters. Table 6-3 summarizes the available touch count parameters. But be warned: the parameters have very small values, like 1 and 2. Therefore, even a switch from 1 to 2 is a relatively massive change that could easily have unintended consequences. I would consider adjusting the touch count parameters only as a last resort and after testing; otherwise, you'll just be guessing.

The percentage of buffer headers in the hot region. If you want more headers to be considered hot, increase this value. Decreasing this parameter will give buffer headers more time to be touched before encountering a server or database writer process.

The time window in which a buffer header's touch count (x$bh.tch) can be increased by only one. Increasing this parameter decreases the affect of a sudden buffer-centered activity burst, while risking devaluing truly popular buffers.