?undo

undo發(fā)音

英：[?n'du:]　　美：[?n?du]

英：　　美：

undo中文意思翻譯

v. 解開(kāi)；松開(kāi)；取消

undo習慣用語(yǔ)

undo常見(jiàn)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(hù)訪(fǎng)問(wèn)數據庫。

3 、His pride will undo him some day.───他的傲慢總有一天會(huì )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，現在調用撤銷(xiāo)只能挽回一個(gè)單詞，6個(gè)段落永遠丟失了。

5 、Undo operates on a user’s actions.───先考慮撤銷(xiāo)針對的對象，即用戶(hù)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(xiě)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(xiāo)呢?

9 、I wish I could undo it, but I can't.─── 我希望我能撤銷(xiāo) 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(huì )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(huì )很容易地從墻上掉下來(lái).

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

13 、If the data is already transactionally consistent at the start of the recovery process, the undo phase is skipped.───如果數據在恢復過(guò)程開(kāi)始時(shí)在事務(wù)方面已經(jīng)是一致的,則將跳過(guò)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(gè)數據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(dòng)。

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(huì )犯錯誤，它不需要什么撤銷(xiāo)功能。

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

18 、If I could undo it, believe me, I would.─── 如果我能撤銷(xiāo)這件事 相信我 我一定會(huì )的

19 、It seemed to undo some of the mischief of the evening.───似乎這天晚上那場(chǎng)惡作劇已經(jīng)一筆勾銷(xiāo)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(wú)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),然后調用進(jìn)程中數據訪(fǎng)問(wèn)。

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(lái)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(zhù)生命危險，企圖扭轉過(guò)去。

26 、During the course of editing, undo, and redo, the model is the only thing that endures.───在編輯、撤銷(xiāo)和重做的過(guò)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(xiāo)工具很容易使用和理解，用戶(hù)就不會(huì )受到無(wú)謂的干擾。

28 、F the errors oon thhis line and reeplace them witth undo.───可以執行恢復命令，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(fēng)格進(jìn)行開(kāi)發(fā)的用戶(hù)，類(lèi)似描述就是需要撤銷(xiāo)簽出。

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

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

33 、To support the actions you take most frequently, such as save and undo, there's the Quick Access Toolbar (QAT).───為了支持您最常執行的操作(如保存和撤消),它提供了“快速訪(fǎng)問(wèn)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(hù)對撤銷(xiāo)功能有著(zhù)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(kāi)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據或計算機,Access無(wú)法彌補。

37 、What exactly is meant by Multiple Level Undo?───多級撤消到底意味著(zhù)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(shí)，撤銷(xiāo)和恢復實(shí)際上是一個(gè)功能，而不是兩個(gè)。

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

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

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

42 、She prepared to undo the band of cloth around his arm which had served as tourniquet.───她準備解開(kāi)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(gè)單獨的密鑰來(lái)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(hù)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(gè)層次的，在撤銷(xiāo)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(dòng)撤銷(xiāo)管理簡(jiǎn)介”了解關(guān)于撤銷(xiāo)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，想把繩結解開(kāi)。

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(zhù)相同的血。我正好可以用你的血來(lái)解除父親的封印。

50 、What are the implications of category-specific Undo in a nontext program?───分類(lèi)撤銷(xiāo)對于非文本程序來(lái)說(shuō)意味著(zhù)什么?

51 、You can unsay what you said,but you can't undo what you did.───你說(shuō)的話(huà)可以賴(lài)掉，但你干的事是賴(lài)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(gè)操作，“撤消”命令會(huì )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(lái)操作文件和撤銷(xiāo)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(gè)階段,并可以恢復數據庫;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.───只有遠程數據庫支持串行化隔離模式時(shí)，事務(wù)發(fā)生錯誤后才能撤銷(xiāo)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(shí)用另外一把扳手擰開(kāi)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(dòng)。

60 、For some users, the absence of this simple Undo is sufficient grounds to abandon a product entirely.───對于某些用戶(hù)來(lái)說(shuō)，缺少簡(jiǎn)單的撤銷(xiāo)功能，可能就會(huì )完全放棄某個(gè)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(guò)去的話(huà)我會(huì )的

62 、You cannot undo or redo a folder action while the folder is loading.───在裝入文件夾期間無(wú)法復原或重做一個(gè)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(dòng),請單擊“游戲”菜單,然后單擊“撤消”,您會(huì )失去兩個(gè)點(diǎn)數。

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(zhù)繞到屋子后邊，打算松開(kāi)繩子讓那滿(mǎn)滿(mǎn)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“系統還原”,則無(wú)法撤銷(xiāo)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據。

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(lái)前滾到一致?tīng)顟B(tài),并撤銷(xiāo)表空間來(lái)回滾任何未提交數據。

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

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

71 、She could not undo the string of the parcel--she was all fingers and thumbs.───她怎么也解不開(kāi)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.───在本節中我們定義幾種撤銷(xiāo)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(cháng)。

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(shí)現文件刪除的撤銷(xiāo)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(huà)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(zhù)我,年復一年優(yōu)雅地將一位老人松綁會(huì )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(dòng)事務(wù)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(xiāo)存在的問(wèn)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(guò)程,從而還原未提交的事務(wù)。

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(huì )監視更改通知來(lái)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(huì )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(lái)撤消上一個(gè)命令或刪除最后鍵入的內容。

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

數據庫恢復是 對沒(méi)提交的失誤為什么要undo

undo和redo是沒(méi)有關(guān)系的，不能相互取代，對于數據庫來(lái)說(shuō)，只有有沒(méi)有undo、和有沒(méi)有redo的區別，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(méi)搞明白這四個(gè)策略是什么意思吧。

steal：允許在事務(wù)commit之前把內存中的數據寫(xiě)入磁盤(pán)。此時(shí)需要undo，因為系統在commit之前崩潰時(shí)，已經(jīng)有數據寫(xiě)入到磁盤(pán)了，要恢復到崩潰前的狀態(tài)，必須undo這些寫(xiě)入操作，否則磁盤(pán)上的數據就是不正確的。

no steal：不允許在事務(wù)commit之前把內存中的數據寫(xiě)入磁盤(pán)。不需要undo。

force：內存中的數據最晚在commit的時(shí)候寫(xiě)入磁盤(pán)。不需要redo。

no force：內存中的數據可以一直保留，在commit之后過(guò)一段時(shí)間再寫(xiě)入磁盤(pán)。此時(shí)需要redo，因為數據在系統崩潰的時(shí)候可能還沒(méi)寫(xiě)入到磁盤(pán)，如果不redo，磁盤(pán)上的數據就是不完整的。

如果數據庫是steal/no force組合（當前所用企業(yè)級數據庫均采用這個(gè)組合），就需要undo和redo，因為能保證內存調度的靈活性，提高系統性能。

對于你的問(wèn)題，未完成的事務(wù)是不能提交的，你所說(shuō)的提交的意思可能是指先把數據寫(xiě)入磁盤(pán)，就是steal，因此需要undo。

undo系列學(xué)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(lèi)型為L(cháng)OB的，自動(dòng)undo數據的記憶是不支持LOBs，必須設置undo_retention的值來(lái)盡力挽留之。oracle在undo segment header上創(chuàng )建一個(gè)retention table用于記錄相關(guān)undo存儲的提交時(shí)間，從而實(shí)現其保留策略。 最優(yōu)的undo_retention如何計算？ 模糊計算可以借助： 如果你的事務(wù)隔離級別是 serializable或read only ，你可以讓undo_retention稍微長(cháng)于最長(cháng)運行的事務(wù)； 如果你的事務(wù)隔離級別是read commited，你可以讓undo_retention稍微長(cháng)于最長(cháng)運行的語(yǔ)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(shí)間段來(lái)測試，或者去多段，然后加權平均