oracle数据库处于open状态时，执行alter database archivelog命令会发生什么？ 操作会被拒绝，需要先关闭数据库 Oracle中如下用于创建PRODUCTS表的SQL语句，以下哪个陈述是正确的？ CREATE TABLE products (product_id NUMBER(3) PRIMARY KEY, product_desc VARCHAR2(25), qty NUMBER(8,2), rate NUMBER(10,2), total_value AS ( qty * rate)) PARTITION BY RANGE (total_value) (PARTITION p1 VALUES LESS THAN (100000), PARTITION p2 VALUES LESS THAN (150000), PARTITION p3 VALUES LESS THAN (MAXVALUE)) COMPRESS FOR ALL OPERATIONS; 它成功执行，但TOTAL_VALUE列中的值不会物理存储在分区上。 You create a new pluggable database, HR_PDB, from the seed database.Which three tablespaces are created by default in HR_PDB? (Choose three.)默认创建了哪三个表空间? 默认情况下，在hr_pdb中创建哪三个表空间 system,sysaux,temp