concurrent transaction 中文意思是什麼

concurrent transaction 解釋
并行事務
  • concurrent : adj 1 同時發生的，並發的，並存的，共存的；合作的。2 （意見）一致的。3 【動物；動物學】趨合的；【...
  • transaction : n 1 辦理，處理；交易；業務，事務。2 【法律】和解。3 〈pl 〉（學會等的）會議記錄；學報。4 【心理學...
  1. This paper decomposes materialized views maintenance into ods / db interface and dw / ods interface. multiple data sources with concurrent updates may result in update anomalies of the materialized views. so at ods / db interface this paper introduces an improved nested transaction model - based transaction concurrency control mechanism to maintenance views in ods on line

    本文把視圖的一致性維護問題分解到三層結構的ods / dw和dw / ods兩個介面上分別實現，並且引入視圖生成樹的概念，在ods / db介面處採用基於改進嵌套事務模型的並發控制機制，聯機維護ods的數據，大大提高了視圖維護過程中的並發度和靈活性。
  2. A transaction is a unit of isolation and each occurs separately and independently of concurrent transactions

    事務是一個隔離單元，並發事務中的每個事務在發生時都相互分離，彼此獨立。
  3. If a lock escalation attempt fails because of conflicting locks held by concurrent transactions, the database engine will retry the lock escalation for each additional 1, 250 locks acquired by the transaction

    如果由於並發事務所持有的鎖沖突而導致鎖升級嘗試失敗，則數據庫引擎將對事務獲取的其他1 ， 250個鎖重試鎖升級。
  4. Conversely, a query holding a sch - s lock blocks a concurrent transaction that attempts to acquire a sch - m lock

    相反，持有sch - s鎖的查詢將阻塞嘗試獲取sch - m鎖的並發事務。
  5. This isolation level eliminates the possibility that one transaction could overwrite changes made by another concurrent transaction ( the second lost updates problem ) if all data access is performed in a single atomic database transaction

    如果所有的數據訪問都是在統一的原子數據庫事務中，此隔離級別將消除一個事務在另外一個並發事務過程中覆蓋數據的可能性（第二個事務更新丟失問題） 。
  6. Then, the paper summaries disadvantages of traditional concurrency controls under multilevel security condition and introduces multilevel security dbms concurrency control. after summarizing the related research work, we present a multi level transaction model to solve the convert channel and starvation problems in concurrent control under blp multi level security model

    本文首先分析了傳統的數據庫並發控制各自存在的優缺點，總結了傳統並發控制在多級安全條件下存在的問題，由此引出了多級安全數據庫並發控制機制。在總結了已有的研究基礎上，針對blp多級安全模型下並發控制產生隱通道和饑餓問題，本文提出了一種多級事務模型- - - nhstm模型。
  7. Serialization does not offer any transaction control mechanisms per se, so it cannot be used within applications that need concurrent access without making use of additional apis

    序列化本身並不提供任何事務控制機制，因此不能在那些需要並發訪問從而不使用輔助api的應用程序中使用它。
  8. When one transaction holds a lock on an item, no concurrent transaction can read and / or modify this item

    當一個事務對一個數據擁有了鎖，那麼其他並發事務則無法對它進行讀或者寫。
  9. Because of this, queries are blocked when a concurrent transaction holds a sch - m schema modification lock on the table

    因此，當並發事務持有表的sch - m （架構修改）鎖時，將阻塞查詢。
  10. The following code example shows how to create a dependent transaction to manage two concurrent tasks by cloning a dependent transaction and passing it to a worker thread

    下面的代碼示例說明如何通過克隆依存事務並將其傳遞到輔助線程，創建依存事務以管理兩個並發任務。
  11. A transaction either recognizes data in the state it was in before another concurrent transaction modified it, or it recognizes the data after the second transaction has completed, but it does not recognize an intermediate state

    事務識別數據時數據所處的狀態，要麼是另一併發事務修改它之前的狀態，要麼是第二個事務修改它之後的狀態，事務不會識別中間狀態的數據。
  12. As the application of distributed computing is used much more widely ， distributed database becomes a significant part of information management it avoids a lot of disadvantages of conventional centralized database ， and is applicable to many situations distributed database is a set of data which is the unity logic ， but in fact these data is located on different sites it is of high availability ， easy expansibility ， high concurrency ， high efficiency and etc in distributed system ， data redundancy is a method to improve the speed of query and the availability of system distributed query should shield the lower level details of data redundancy from end users ， distributed transaction should ensure data from disaccord this paper introduces basic conceptions of distributed database firstly ， discusses distributed transaction and concurrent control ， describes the development prototype mysql ’ s characters ， architecture and executive mechanism ， then shows the skeleton model of dpsql and exposes the strategy and algorithm of distributed query and distributed transaction ， at last analyzes the extra expenses and response delay of distributed processes this paper exposes the implementation mechanism of distributed query and distributed transaction emphatically distributed query uses the strategy of “ read one ， write a11 ” s0 in such a system if user ’ s requests are read - - only for the most part and the distribution of data redundancy is plausible ， efficiency is very high distributed transaction uses two - 。 phase commit protocol to ensure the consistency of global data ， which has less communication overhead

    分散式查詢需要向用戶屏蔽數據冗餘分散的底層細節，分散式事務處理要保證全局數據完整，這都是傳統集中式數據庫不曾面臨的問題。本文首先介紹了分散式數據庫的概念性問題；接著討論了分散式事務涉及的定義及演算法；然後描述了dpsql的原型mysql的特性、結構和執行機制；繼而給出了dpsql的梗概模型，闡述了實現分散式查詢和分散式事務處理的策略及演算法；最後分析了進行分散式處理給系統增加的額外開銷和客戶端的額外響應延遲。本文重點描述了分散式查詢和分散式事務處理的實現機制，分散式查詢採用」讀一個寫全部」的本地優先策略，在讀操作頻繁的系統中，只要庫的分佈合理，單機效率極高，幾乎無任何附加開銷和延遲，而以整個系統的角度看來，吞吐量就更是優于單機系統；分散式事務處理採用兩階段提交協議，通信次數較少並能確實保證副本一致。
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