READ Free Dumps For Oracle- 1z0-117
| Question ID 2500 | Which three statements are true about histograms? |
| Option A | A. They capture the distribution of different values in an index for better selectivity estimates. |
| Option B | B. They can be used only with indexed columns. |
| Option C | C. They provide metadata about distribution of and occurrences of values in a table column. |
| Option D | D. They provide improved selectivity estimates in the presence of data skew, resulting in execution plans with uniform distribution. |
| Option E | E. They help the optimizer in deciding whether to use an index or a full table scan. |
| Option F | F. They help the optimizer to determine the fastest table join order. |
| Correct Answer | C,E,F |
| Question ID 2501 |
View the exhibit and examine the query and its execution plan from the PLAN_TABLE. Which statement is true about the execution? |
| Option A | A. The row with the ID column having the value 0 is the first step execution plan. |
| Option B | B. Rows are fetched from the indexes on the PRODUCTS table and from the SALES table using full table scan simultaneously, and then hashed into memory. |
| Option C | C. Rows are fetched from the SALES table, and then a hash join operator joins with rows fetched from indexes on the PRODUCTS table. |
| Option D | D. All the partitions of the SALES table are read in parallel. |
| Correct Answer | C |
