In the evening I noticed that Adam's scorpion, a Heterometrus
silenus, was out of hiding and wandering around in its enclosure
clearly looking for food. So I carefully removed the two enclosures
resting atop the lid and then removed the lid and gave the scorpion a
mealworm with a pair of tweezers. It grabbed the tweezers instead of
the mealworm and the mealworm dropped on the substrate.
But because the mealworm moved slightly against the first right leg of
the scorpion it started to feel around with its claws and
finally found the nice snack.
Speeding up SQL queries by orders of magnitude using UNION
One of the most common cases where SQL query performance can degrade
significantly is in a diamond shaped schema, where there are
multiple ways of joining two tables together. In such a schema, a
query is likely to use OR to join tables in more than one way, which
eliminates the optimizer’s ability to create an efficient query