密封的V型圈数量取决于密封（）的大小。 压力。 压强。 温度。 管口。
You work as a database administrator for Certkiller .com. You have set the retention period for Automatic Repository （AWR） statistics to four days and collection interval to 15 minutes. You want to view the statistics collected and stored in AWR snapshot. Which two methods would you use to view the AWR statistics？（） use enterprise manager。 use DBMS_SQL package。 use DBMS_AWR package。 use PRVT_WORKLOAD package。 query the AWR snapshot repository objects。 use DBMS_WORKLOAD_REPOSITORY package。
避雷带应每隔（）m设置一支撑杆，支撑杆露出墙面部分的高度应不小于15cm，插入墙内的深度不小于10cm，插入支撑杆前先将钻孔时产生的粉末清理干净后，再将支撑杆一端涂上沥青，并且支撑杆应尽量保持在同一直线上。 0.8。 1.0。 1.2。 1.5。
You work as a database administrator for Certkiller .com. As a result of performance analysis， you created an index on theprod_namecolumn of the Certkiller prodtable， which contains about ten thousand rows. Later， you updated a product name in the table. How does this change affect the index？（） A leaf will be marked as invalid.。 An update in a leaf row takes place.。 The index will be updated automatically at commit.。 A leaf row in the index will be deleted and inserted.。 The index becomes invalid when you make any update。
运动单位
器的直径（）爆炸上、下限的差距也越小，发生爆炸的危险性降低
