A user executes a query on the EMPtable， which contains thousands of rows， to get details about employees in one of the departments. The user receives the following error： SQL> SELECT ename FROM emp WHERE deptno=10 ORDER BY sal； SELECT ename FROM emp WHERE deptno=10 ORDER BY sal ERROR at line 1： ORA-01157： cannot identify/lock data file 201 - see DBWR trace file ORA-01110： data file 201：’/u01/app/oracle/oradata/orcl/temp01.dbf’ What is a possible reason？（） [" The tempfile belonging to the default temporary tablespace is missing."," The database is opened in restricted mode， so queries are not allowed"," The default temporary tablespace required to execute the query is offline."," The default temporary tablespace required to execute the query is dropped."," The default temporary tablespace required to execute the query is read-only."]
论述往复式压缩机润滑的目的。
You conned using SQL Plus to the root container of a multitenant container database (CDB) with SYSDBA privilege. The CDB has several pluggable databases (PDBs) open in the read/write mode. There are ongoing transactions in both the CDB and PDBs. What happens alter issuing the SHUTDOWN TRANSACTIONAL statement?（） [" The shutdown proceeds immediately. The shutdown proceeds as soon as all transactions in the PDBs are either committed or rolledhack."," The shutdown proceeds as soon as all transactions in the CDB are either committed or rolled back."," The shutdown proceeds as soon as all transactions in both the CDB and PDBs are either committed or rolled back."," The statement results in an error because there are open PDBs."]
Identify the memory component from which memory may be allocated for: （） 1: Session memory for the shared server 2: Buffers for I/O slaves 3: Oracle Database Recovery Manager (RMAN) backup and restore operations ["Large Pool","Redo Log Buffer","Database Buffer Cache","Program Global Area （PGA）"]
开关燃弧时间与刚分速度关系是（）。 [".正比","无关","反比"]
宋代理学家周敦颐融合道教的太极理论，配置出太极生化万物之图，还专门写下了《（）》来阐述其思想。
