?undo

undo發(fā)音

英：[?n'du:]　　美：[?n?du]

英：　　美：

undo中文意思翻譯

v. 解開；松開；取消

undo習慣用語

undo常見例句

1 、Ah, don't let us undo what you've done.───啊，不要讓我們改變你們已經(jīng)決定了的事。

2 、During the undo phase of a crash recovery, SQL Server 2005 lets users access the database.───在崩潰了的恢復的撤消階段,SQL Server 2005允許用戶訪問數(shù)據(jù)庫。

3 、His pride will undo him some day.───他的傲慢總有一天會毀了他。

4 、Unfortunately, performing Undo now merely brings back the one word, and the six paragraphs are lost forever.───不幸的是，現(xiàn)在調(diào)用撤銷只能挽回一個單詞，6個段落永遠丟失了。

5 、Undo operates on a user’s actions.───先考慮撤銷針對的對象，即用戶的操作。

6 、The Donaghy scandal "has harmed the NBA and caused it to spend vast sums to undo that harm," league lawyers wrote.───多納蒂丑聞“已經(jīng)傷害了NBA，并導致聯(lián)盟花費巨大以彌補這些傷害?！甭?lián)盟律師寫道。

7 、She can undo any mess that her brothers, Set and Osiris, create.───她可以解除她的兄弟塞特和歐西里斯制造的任何混亂。

8 、Why isn’t a filename Undo provided?───為什么不提供文件名撤銷呢?

9 、I wish I could undo it, but I can't.─── 我希望我能撤銷 但我做不到

10 、Tampering with this symbiotic relationship may undo her, undo ourselves, and therein lies the rub with bioengineering.─── 若這種共生關(guān)系受到損害 她可能會遭到毀滅 也毀掉我們自己 所以生物工程才非常重要

11 、The mirror comes off the wall very easily,if you just undo those screws.───如果你要把那些螺釘擰松,鏡子就會很容易地從墻上掉下來.

12 、As a computational facility, Undo has no merit.───作為計算機的一項功能，撤銷沒有什么優(yōu)點。

13 、If the data is already transactionally consistent at the start of the recovery process, the undo phase is skipped.───如果數(shù)據(jù)在恢復過程開始時在事務方面已經(jīng)是一致的,則將跳過撤消階段。

14 、To return a database to its state as of the last committed change, i.e., to undo recent uncommitted changes.───使一個數(shù)據(jù)庫返回到它上次已確認的改變之后的狀態(tài)，即取消最近的尚未確認的變動。

15 、...competition that was to be their undoing.─── 惡性競爭導致了他們的覆滅

16 、Mistake-free as they are, computers have no need for Undo.───因為計算機本身不會犯錯誤，它不需要什么撤銷功能。

17 、Once you do this, there's no undoing it.─── 一旦你決定這么做 就無法反悔了

18 、If I could undo it, believe me, I would.─── 如果我能撤銷這件事 相信我 我一定會的

19 、It seemed to undo some of the mischief of the evening.───似乎這天晚上那場惡作劇已經(jīng)一筆勾銷了。

20 、Doing it to her doesn't undo what she did to me.─── 羞辱她并不能彌補她對我的羞辱

21 、Also, remember that once you delete a whole record, you cannot undo that deletion.───另外請記住,一旦刪除了整條記錄,將無法撤消該刪除操作。

22 、Code can undo the impersonated state, and then call in-process data access.───代碼可以取消模擬狀態(tài),然后調(diào)用進程中數(shù)據(jù)訪問。

23 、As a result, the undo engine has control over the duration of an undoable action.───因此,撤消引擎擁有對可撤消操作期間的控制權(quán)限。

24 、It is he who is coming after me; I am not good enough to undo his shoes.───27就是那在我以后來的，我給他解鞋帶，也不配。

25 、But now, this brave Cambodian risks his life to undo his past.───但如今，這名勇敢的柬埔寨人冒著生命危險，企圖扭轉(zhuǎn)過去。

26 、During the course of editing, undo, and redo, the model is the only thing that endures.───在編輯、撤銷和重做的過程中,模型是唯一保持不變的。

27 、If the undo facility is sufficiently easy to use and understand, users won’t be bothered by it.───如果撤銷工具很容易使用和理解，用戶就不會受到無謂的干擾。

28 、F the errors oon thhis line and reeplace them witth undo.───可以執(zhí)行恢復命令，也就是撤消掉撤消命令。

29 、With Multiple Level Undo you can safely experiment with various what-if scenarios.───使用多級撤消可以安全地嘗試各種假設分析方案。

30 、For users who use the checkout-edit-checkin style of development, closely related here is the need to undo a checkout.───對于使用簽出-編輯-簽入風格進行開發(fā)的用戶，類似描述就是需要撤銷簽出。

31 、Select the drive where the undo information was previously saved.───在以前保存恢復信息的驅(qū)動器列表中選擇驅(qū)動器

32 、Would you please undo this knot for me?───你能不能幫我把這個結(jié)解開？

33 、To support the actions you take most frequently, such as save and undo, there's the Quick Access Toolbar (QAT).───為了支持您最常執(zhí)行的操作(如保存和撤消),它提供了“快速訪問工具欄”(QAT)。

34 、Users visualize the Undo facility in different ways, depending on the situation and their expectations.───取決于各種情況和期望，用戶對撤銷功能有著不同的形象化理解。

35 、History may be forgiving to losers, but the manner of their exits can still undo them.───歷史可以寬恕失敗者，但他們離開的方式仍然可以毀滅他們。

36 、If malicious code harms your data or your computer, Access cannot undo that damage.───如果惡意代碼損壞了數(shù)據(jù)或計算機,Access無法彌補。

37 、What exactly is meant by Multiple Level Undo?───多級撤消到底意味著什么?

38 、When used as comparison functions, Undo and Redo are really one function and not two.───在使用比較功能時，撤銷和恢復實際上是一個功能，而不是兩個。

39 、During process compensation, all of the undo services of successfully completed invoke activities are run.───在流程補償期間,已成功完成的調(diào)用活動的所有撤銷服務都要運行。

40 、Redo prevents a diabolical situation in multiple Undo.───在多次撤銷中，恢復能避免糟糕情形的出現(xiàn)。

41 、He tried to undo the knot by picking at it with ihs fingers.───他用手指不停地扯,想把繩結(jié)解開。

42 、She prepared to undo the band of cloth around his arm which had served as tourniquet.───她準備解開纏在他胳臂上止血的布帶。

43 、The keys must be used together: each individual key cannot be used to undo its own operation.───密鑰必須配合使用:不能使用每個單獨的密鑰來撤消它自己的操作。

44 、Your application's user interface for undo may differ from the one describe below.───對于撤消命令，您的應用程序用戶接口可能不同于下面描述的。

45 、Access maintains a list of the last 20 actions and lets you undo each, in sequence.───Access保持了最近20項操作的列表,允許您按順序撤消每一項操作。

46 、It is multiple level, showing a textual description of each operation in the Undo stack.───它是多個層次的，在撤銷堆棧中顯示了每次操作的文字描述。

47 、See Also: "Introduction to Automatic Undo Management" for more information about managing undo space.───“自動撤銷管理簡介”了解關(guān)于撤銷空間管理的更多信息。

48 、He tried to undo the knot by picking at it with his fingers.───他用手指不停地扯，想把繩結(jié)解開。

49 、Why not? After all we share the same blood. I'll just use more of yours to undo daddy's little spell.───為什么不?畢竟我們流著相同的血。我正好可以用你的血來解除父親的封印。

50 、What are the implications of category-specific Undo in a nontext program?───分類撤銷對于非文本程序來說意味著什么?

51 、You can unsay what you said,but you can't undo what you did.───你說的話可以賴掉，但你干的事是賴不掉的。

52 、The undo command change to can not undo on the menu if you cannot reverse your last action.───如果不能退回最后一個操作，“撤消”命令會變化到菜單上的“不能撤消”命令。

53 、You can use the terminal as a file browser to navigate your files and undo the changes that have been made.───你可以使用終端用作文件瀏覽器來操作文件和撤銷你所作出的更改。

54 、WITH RECOVERY includes both the redo and undo phases and recovers the database; additional backups cannot be restored.───WITH RECOVERY包含重做和撤消兩個階段,并可以恢復數(shù)據(jù)庫;不能還原其他備份。

55 、You do and undo at every step.───你每一步伐都在建造和拆卸。

56 、The GIMP can undo most changes to the image, so feel free to experiment.───GIMP 幾乎可以還原所有更改影像的操作程序，因此您可以放心嘗試。

57 、The transaction can undo and retry only when the remote server does support serializable transactions.───只有遠程數(shù)據(jù)庫支持串行化隔離模式時，事務發(fā)生錯誤后才能撤銷并重試。

58 、You hold the lower nut with one spanner while you undo the top nut with another one - do you see what I mean?───你用板手固定住下面螺母，同時用另外一把扳手擰開上面螺母，你明白的意思嗎?

59 、This allows the creator to easily undo a change.───使得創(chuàng)建人能輕松撤消某項改動。

60 、For some users, the absence of this simple Undo is sufficient grounds to abandon a product entirely.───對于某些用戶來說，缺少簡單的撤銷功能，可能就會完全放棄某個產(chǎn)品。

61 、If I could undo it, I would. I swear.─── 我發(fā)誓 如果我能退回到過去的話我會的

62 、You cannot undo or redo a folder action while the folder is loading.───在裝入文件夾期間無法復原或重做一個文件夾操作。

63 、If you want to erase a move, click the Game menu, and then click Undo, and you will lose two points.───如果要清除一次移動,請單擊“游戲”菜單,然后單擊“撤消”,您會失去兩個點數(shù)。

64 、I need to undo it, I absolutely have to undo it.─── 我得撤掉 一定要把這些拿走

65 、He ran round behind the house, intending to undo the rope in order to let fall the pailful of water upon Tommy Brock.───他跑著繞到屋子后邊，打算松開繩子讓那滿滿的一桶水落在湯米獾身上。

66 、If you use System Restore when the computer is in safe mode, you cannot undo the restore operation.───如果在計算機處于安全模式的情況下使用“系統(tǒng)還原”,則無法撤銷還原操作。

67 、If the changes aren't desirable for your project, you can easily undo them and restore the previous data.───如果更改不適合于項目,則可以輕松地撤消更改并還原以前的數(shù)據(jù)。

68 、Oracle uses archived logs to roll forward to consistent state and Undo table space to rollback any uncommitted data.───Oracle使用歸檔日志來前滾到一致狀態(tài),并撤銷表空間來回滾任何未提交數(shù)據(jù)。

69 、Idea for a new app: an undo button that could undo long amounts of time.─── 一款新應用的構(gòu)想 一個可以 取消很長一段時間的按鍵

70 、Impossible to undo the suffering caused by the war.───不可能清除戰(zhàn)爭引起的痛苦。

71 、She could not undo the string of the parcel--she was all fingers and thumbs.───她怎么也解不開包袱上的繩子。

72 、If you undo an add, the file is left undisturbed.───如果您撤消添加操作,文件將原樣保留。

73 、In this section, we define several Undo variants and explain their differences.───在本節(jié)中我們定義幾種撤銷的變體，并且解釋其不同。

74 、It does not allow someone to exhume memories that are decades old or to retrace or undo human development.───它并不能讓人挖掘出幾十年前的記憶、重新追索或取消人的成長。

75 、The sole reason the Recycle Bin exists is to implement an undo facility for deleted files.───回收站存在的唯一理由就是實現(xiàn)文件刪除的撤銷工具。

76 、You can't undo what's been done. It's done.───你不可能改變已經(jīng)發(fā)生的事情。

77 、Don't show this dialog box again (Always undo checkout).───不再顯示此對話框(總是撤消簽出)。

78 、The undo command returns all checked-out files to a read-only, unmodified state.───undo命令將所有簽出文件返回到未修改的只讀狀態(tài)。

79 、With Multiple Level Undo, can I go back past the last save?───使用多級撤消是否可以恢復到上一次保存以前的狀態(tài)?

80 、And yet she waits for me, year and year, to so delicately undo an old would, to empty my breath from its bad prison.───可她等著我,年復一年優(yōu)雅地將一位老人松綁會從黑牢中解放我的呼吸。

81 、The UNDO_RETENTION parameter works best if the current undo tablespace has enough space for the active transactions.───retention能做好地工作如果----當前的回滾表空間對活動事務有足夠的空間。

82 、The problems with multiple Undo are not due to its behavior as much as they are due to its manifest model.───多次撤銷存在的問題不是因為它的行為，而是因為其顯式模型。

83 、The standby file allows for the undo pass to be reverted so that the uncommitted transactions can be brought back.───使用備用文件可以恢復撤消過程,從而還原未提交的事務。

84 、He wished, half sadly, that he could undo it all.───他有些悲哀，真希望自己能抹掉這一切。

85 、You can quickly undo a calculated column.───可以快速撤消計算列。

86 、She knew it would be difficult to undo the damage that had been done.───她知道很難消除已經(jīng)造成的損害。

87 、Monitors for change notifications to create undo units, and the units themselves consist of serialized object states.───會監(jiān)視更改通知來創(chuàng)建撤消單元,這些撤消單元自身由序列化的對象狀態(tài)組成。

88 、The more that is there, the more there is to undo.─── 不盡早處理 只會越陷越深

89 、Uses the Undo command to reverse the last command or to delete the last entry that you typed.───使用“撤消”命令來撤消上一個命令或刪除最后鍵入的內(nèi)容。

90 、Uses Undo to undo the changes that were shelved.───使用Undo可撤消已擱置的更改。

數(shù)據(jù)庫恢復是 對沒提交的失誤為什么要undo

undo和redo是沒有關(guān)系的，不能相互取代，對于數(shù)據(jù)庫來說，只有有沒有undo、和有沒有redo的區(qū)別，不是有了undo就不能有redo，或者有了redo就不能有undo。

到底用不用redo和undo是和steal、no steal、force、no force策略相關(guān)的。你肯定是沒搞明白這四個策略是什么意思吧。

steal：允許在事務commit之前把內(nèi)存中的數(shù)據(jù)寫入磁盤。此時需要undo，因為系統(tǒng)在commit之前崩潰時，已經(jīng)有數(shù)據(jù)寫入到磁盤了，要恢復到崩潰前的狀態(tài)，必須undo這些寫入操作，否則磁盤上的數(shù)據(jù)就是不正確的。

no steal：不允許在事務commit之前把內(nèi)存中的數(shù)據(jù)寫入磁盤。不需要undo。

force：內(nèi)存中的數(shù)據(jù)最晚在commit的時候?qū)懭氪疟P。不需要redo。

no force：內(nèi)存中的數(shù)據(jù)可以一直保留，在commit之后過一段時間再寫入磁盤。此時需要redo，因為數(shù)據(jù)在系統(tǒng)崩潰的時候可能還沒寫入到磁盤，如果不redo，磁盤上的數(shù)據(jù)就是不完整的。

如果數(shù)據(jù)庫是steal/no force組合（當前所用企業(yè)級數(shù)據(jù)庫均采用這個組合），就需要undo和redo，因為能保證內(nèi)存調(diào)度的靈活性，提高系統(tǒng)性能。

對于你的問題，未完成的事務是不能提交的，你所說的提交的意思可能是指先把數(shù)據(jù)寫入磁盤，就是steal，因此需要undo。

undo系列學習之如何計算最優(yōu)的undo

undo_retention的設置可盡責于閃回功能。對于列的類型為LOB的，自動undo數(shù)據(jù)的記憶是不支持LOBs，必須設置undo_retention的值來盡力挽留之。oracle在undo segment header上創(chuàng)建一個retention table用于記錄相關(guān)undo存儲的提交時間，從而實現(xiàn)其保留策略。 最優(yōu)的undo_retention如何計算？ 模糊計算可以借助： 如果你的事務隔離級別是 serializable或read only ，你可以讓undo_retention稍微長于最長運行的事務； 如果你的事務隔離級別是read commited，你可以讓undo_retention稍微長于最長運行的語句（DML)。 精確計算可以借助公式： 我們需要選一段比較有代表性的時間段來測試，或者去多段，然后加權(quán)平均