Which of these guidelines will reduce potential row migration?
A . Decrease PCTFREE.
B. Increase PCTFREE.
C . Use the DBMS_STATS.unchain procedure.
D . Use the ANALYZE command on the table regularly.
E . Increase PCTUSED.
Explanation:
Answer B: Row migration occurs because there is not enough free space in the data block where the row was initially placed. Increasing the PCTFREE setting will reduce the likelihood of row migration, but the modification does not change existing data blocks. The new settings apply to all data blocks used by the table, including blocks already allocated and subsequently allocated for the table. However, the blocks already allocated for the table are not immediately reorganized when space usage parameters are altered, but are necessary after the change. Once the PCTFREE is changed, DML will utilize the new setting.
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