Index_N

N

natural joins, 99–100

network databases, 3

non-equijoins, 103–105

nonmedia failures, 268

nonunique indexes, 209, 245

NOT NULL constraints, 142–143

NOT operator, and WHERE clause, 76

NULL keyword, 32

NULL values

defined, 32

vs. FALSE values, 82

group functions and, 85, 86, 89

queries and, 48

numeric functions

built-in, 55–58

numeric formatting, 61–62

numeric literals, 50

NVL, 89