Oracle PL/SQL Best Practices

Second Edition Dezember 2007
ISBN 978-0-596-51410-5
292 Seiten
eBook-Format: PDF, EPUB, MOBI
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Kolophon

The animal on the cover of Oracle PL/SQL Best Practices, Second Edition, isa red wood ant. Red wood ants (Formica aquilonia) are often the dominantants of forests throughout the northern hemisphere. F. aquilonia can buildnest mounds of dried spruce needles and twigs that are three feet or more indiameter and height. Each nest can contain thousands of ants as well asseveral queens. The insects have no sting but can defend themselves byfiring formic acid from their rear ends when disturbed.

The workers vary in size up to about half an inch in length with a red thorax,black abdomen, and red and black marked head. The ants are both scavengersand general predators of insects, carrying many soft-bodied caterpillars,flies, and sawflies along their several major trails back to the nest.

Red wood ants are a keystone species (i.e., without them the ecosystemchanges fundamentally). When red ants disappear from a system, herbivorousinsects can subsequently damage forest trees. In forests weakened bypollution and acid rain in central Europe, red wood ant populations areoften endangered, which in turn causes further imbalances in predator-preydynamics and the ecosystem. These rare ants are protected by law in someEuropean countries because of their great value in destroying forest pests.

For 28 years, Professor Seigo Higashi has been studying a supercolony ofJapanese red wood ants (Formica yessensis), which dwell along a strip ofshoreline on the Ishikari coast of northern Japan. When first discovered in1973, the colony consisted of approximately 45,000 nests with connectingtunnels extending nearly 12.4 miles along the shore of the Japan Sea. It wasestimated that the colony had about 306 million workers and 1.1 millionqueens, and is thought to be about 1,000 years old. Since 1973, the colonyhas been under siege, threatened by the development of infrastructure for anew port on Ishikari Bay, which has occurred on top of 30 percent of the antmegalopolis. This has reduced the number of red wood ants living there bymore than half.

The Ishikari ants are one of only two known ant supercolonies in the world.The other, smaller one is in the Swiss Jura mountains.


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