【2019】OCP 12c 062題庫更新大量新題-7

7.daily_ords_lst is created in locally managed tablespace ORDERS_TBS which uses automatic segment space management.

CREATE TABLE daily_ords_list (ordno NUMBER, ord_date DATE) PCTFREE 20;

Which two are true ?

A) 80% of every data block in daily_ords_lst is reserved for row inserts.

B) pctfree eliminates row chaining during inserts.

C) pctfree can help reduce row migration during updates.

D) pctfree can help to minimize row chaining during inserts.

E) 20% of each data block in the table is reserved for row updates.

Answer:CE

(解析:pctfree 目的就是預防在 update 時造成行遷移,空出 20%就是爲了給 update 使用,A 答案爲什麼是錯的呢,因爲塊頭也要佔空間,所以真正使用的時候不會有 80%的可用空間。部落3:1015267481)

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