An index-organized table (IOT) might be the best storage structure to implement, given which of the following conditions? (Choose two.)
A . Rows are frequently deleted and updated to expand character columns.
B . All queries will use full-table scans on the IOT.
C. All queries will use the primary key for lookup.
D. Rows are frequently added, but not updated or deleted.
Explanation:
Answer C and D: IOT's are best suited for physical guess lookups, based on the primary key value. An IOT is also a good choice when there is minimal maintenance required on the index structure. Too many deletes can cause performance problems due to sparsely populated blocks. An IOT must have a primary key.
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