Hour 16, "Using Indexes to Improve Performance"
Quiz Answers
| 1: | What are some major disadvantages of using indexes? |
| A1: | Major disadvantages of an index include slowing batch jobs, storage space on the disk, and maintenance upkeep on the index. |
| 2: | Why is the order of columns in a composite important? |
| A2: | Because query performance is improved by putting the column with the most restrictive values first. |
| 3: | Should a column with a large percentage of NULLs be indexed? |
| A3: | No. A column with a large percentage of NULLs should not be indexed, because the speed of accessing these rows degrades when the value of a large percentage of rows is the same. |
| 4: | Is the main purpose of an index to stop duplicate values in a table? |
| A4: | No. The main purpose of an index ... |
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