QUESTION: How are null values treated when one or more appears during the execution of a group function? [signinlocker] ANSWER: Null values in a column are ignored. [/signinlocker]
QUESTION: “Which forecasting technique can place the most emphasis on recent values? How does it do this?” [signinlocker] ANSWER: Exponential smoothing weighs all previous values with a set of weights that decline exponentially. It can place full weight on the most recent period (with an alpha of 1.0). This, in effect, is the naïve approach, …
Amazon 10K 2019 Annual report which provides a comprehensive overview of the company for the past year. [signinlocker] [/signinlocker]
Amazon 10K 2017 Annual report which provides a comprehensive overview of the company for the past year. [signinlocker] [/signinlocker]
Amazon 10K 2018 Annual report which provides a comprehensive overview of the company for the past year. [signinlocker] [/signinlocker]
QUESTION: “What do the ALL and ANY operators do when used in a subquery?” [signinlocker] ANSWER: ALL specifies that a condition is true for all values in a set of values. ANY specifies that the condition is true for at least one value in a set of values. [/signinlocker]
QUESTION: “What is the SQL operator (i.e., keyword) used in conjunction with pattern matching?” [signinlocker] ANSWER: The LIKE operator is used in conjunction with pattern matching. [/signinlocker]
QUESTION: What is the result of an attempt to add, subtract, multiply, or divide two number fields, one of which contains a null value? [signinlocker] ANSWER: The Inclusion of a null value results in each of these computations yielding a null value as the result. [/signinlocker]
QUESTION: Which comparison operators can be used when searching for null values? Which comparison operators cannot be used when searching for null values? What is the result when these unacceptable comparison operators are used when searching for null values? [signinlocker] ANSWER: None of the comparison operators except for IS NULL or IS NOT NULL can …
QUESTION: What is the difference between a character field that contains a null value and a character field that contains a single blank space? [signinlocker] ANSWER: A character field that contains a null value is zero characters long, while a character field that contains a single blank space has a length of one character. [/signinlocker]