Optimizing Oracle Performance

Glossary

Amdahl’s law

A vital insight recognized by Gene Amdahl [Amdahl (1967)], which allows a performance analyst to compute the relevance of various proposed performance improvements:

The performance enhancement possible with a given improvement is limited by the fraction of the execution time that the improved feature is used.

Arrival rate (λ)

The rate of arrivals into a queueing system per unit of time during a specified time interval.

Chi-square goodness-of-fit test

A statistical test that is useful in determining whether a data sample is sufficiently likely to belong to a specified distribution.

Clock interrupt

An interrupt that notifies the operating system kernel that one more time interval has elapsed [Bovet and Cesati (2001) 140].

Closed form solution

A mathematical result that can be expressed exactly in symbolic form. Contrast a mathematical result that can be expressed only approximately in numeric form.

Code path

The computer instructions that are executed to produce a given result. Code path reduction is the process of improving performance by eliminating code path without diminishing the functional result.

Collateral benefit

An unintended positive side effect of an action. A benefit yielded serendipitously by attending to something else.

Collateral damage

An unintended negative side effect of an action.

Completion rate (X)

The throughput of a queueing system.

Compulsive tuning disorder (CTD)

A term created by Gaja Vaidyanatha and Kirti Deshpande to describe an effect of using a performance ...