气体的黏度随温度的升高而升高,而液体的黏度随温度的降低而升高。
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扬程为20m的离心泵,不能把水输送到20m的高度。
Uponstartingyourdatabase,youreceivethefollowingerror:
SQL>startupORACLEinstancestarted.
TotalSystemGlobalArea171581440bytesFixedSize1298640bytesVariableSize146804528bytesDatabaseBuffers20971520bytesRedoBuffers2506752bytesDatabasemounted.
ORA-00313:openfailedformembersofloggroup1ofthread1
ORA-00312:onlinelog1thread1:’/oracle01/oradata/orcl/redo01.log’ORA-00312:onlinelog1thread1:’/oracle01/oradata/orcl/redo01a.log’
Youcanchoosefromthefollowingsteps:
a.Restorethedatabasedatafiles.
b.Issuethealterdatabaseclearunarchivedlogfilegroup1command.
c.Issuethealterdatabaseopencommand.
d.Issuethealterdatabaseopenresetlogscommand.
e.Recoverthedatabaseusingpoint-in-timerecovery.
f.IssuetheStartupMountcommandtomountthedatabase.
g.Backupthedatabase.
Whichisthecorrectorderofthesestepsinthiscase?()