..
1 0 0 0 0 1 ...
0 1 1 0 1 0 ...
partno color size weight
1
2
3
4
5
6
GREEN
RED
RED
BLUE
RED
GREEN
MED
MED
SMALL
LARGE
MED
SMALL
98.1
1241
100.1
54.9
124.1
60.1
... ...
PARTS table
96 | Chapter 4: Oracle Data Structures
As of Oracle Database 10g, youcan perform case- or accent-insensitive
queries; these queries provide another way to solve this problem.
This capability becomes even more valuable when you consider that you can create
your own functions in an Oracle database. You can create a very sophisticated function
and then create an index based on the function, which can dramatically affect
the performance of queries that require the function.
Invisible indexes
Oracle Database 11g introduces a new option for all of the index types we??™ve discussed
in previous sections??”the invisible index. Normally, all indexes are used by
the optimizer, which is described later in this chapter. Youcan eliminate an index
from optimizer consideration by taking the index offline or by deleting the index. But
with both of these methods youwill have to take some actions to bring the index up
to date when you bring it back into the database environment.
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