You are administering a database supporting an OLTP workload where the users perform frequent queries for fetching a new rows as possible, involving join operations on recently inserted data. In…

Question

Exhibit

Options

• ASet the OPTIMIZER_MODE initialization parameter to FIRST_ROWS_n.
• BAdd the hint ALL_ROWS in the DOS queries.
• CSet the OPTIMIZER_INDEX_CACHING initialization parameter to 0.
• DAdd a hint INDEX_COMBINE in all DSS queries.
• ESet the OPTIMIZER_INDEX_COST_ADJ initialization parameter to 100.

• A
  78% (21)
• B
  4% (1)
• C
  15% (4)
• D
  4% (1)

Explanation

The last appended rows are more likely to be found quickly with FIRST_ROWS_n. E: Make it not to prioritize index instead if table scan. OPTIMIZER_INDEX_COST_ADJ OPTIMIZER_INDEX_COST_ADJ lets you tune optimizer behavior for access path selection to be more or less index friendly--that is, to make the optimizer more or less prone to selecting an index access path over a full table scan. The default for this parameter is 100 percent, at which the optimizer evaluates index access paths at the regular cost. Any other value makes the optimizer evaluate the access path at that percentage of the regular cost. For example, a setting of 50 makes the index access path look half as expensive as normal.

No community discussion yet for this question.