relational algebra 中文意思是什麼
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In addition, because there is internal relationship between the formalism of relational database, " relational algebra ", and the clausal logic used by ilp, ilp methods can directly deal with mining task involved in multiple tables of relational database
此外，由於關系數據庫的形式描述? 「關系代數」與ilp的子句邏輯有著內在的關聯性， ilp技術可被直接用於涉及關系數據庫中多個關系（表）的數據挖掘任務。 -
Many mature technologies on this level have been brought out, such as the relational algebra law, the improved logical query plan, the cost estimation of operation, the selective plan based on cost and order of joint, etc. although many methods have been tried out, no remarkable result or noteworthy technology has come to reality because of complexity of data decomposition and network effects
例如，從物理查詢計劃的底層磁盤輸入輸出到語法分析階段的語法分析樹、用於改進查詢計劃的代數定律、邏輯查詢計劃的改進，以及操作代價的估計、基於代價的計劃和連接順序的選擇等全過程，都進行了不懈的努力。在這方面的研究已經非常成熟。 -
An approach to formalize and evaluate relational algebra operations by means of xdd is presented. a query is formalized as one or more xml clauses and evaluated by employment of equivalent transformation of xdd
提出了根據關系代數表達式構造查詢子句的方法，關系代數表達式可以用若干個xml子句描述，並通過等價變換得到查詢結果，證明了該方法的正確性。 -
We use a navigational algebra as the target ganguage the describes navigation plans and we show how to us rewrite rules in the spirit of relational optimizers and, taking link and inclusion constraints into account, to reduce the number of page accesses needed to answer a query
我們使用引導代數（ navigationalalgebra ）作為描述導航方案的目標語言，同時我們在研究最優化關系抽象中使用重寫規則，將鏈接約束和包含約束引入到運算中，以便在回答查詢中，減少大量需要訪問的頁面數量。 -
Topics include : relational databases, sql ( structured query language ) ; types, relations, relational algebra, integrity, view ; functional dependency theory, normalization, semantic modeling, entity - relationship modeling, conceptual database design ; concurrency control, security ; database and web connectivity, xml
主題包括:關聯式資料庫、 sql （結構查詢語言） ;資料類型、關聯、關聯式代數、完整性、景觀表;功能依附理論、正規化、語義塑模、實體關聯塑模、概念性資料庫設計;同時操作控制、安全;資料庫與網頁連結、 xml （可擴展標示語言） 。 -
In relational databases, an operator in relational algebra
在關系數據庫中，關系代數用的一種運算符。 -
It is implied by the associative and commutative transformations permitted in relational algebra
它由關系代數中允許的關聯轉換和交換轉換表示。 -
Leap is an rdbms ( relational database management system ) implementing the relational algebra - a core part of relational database theory
Leap是一個rdbms ，它實現了關系代數，關系數據庫理論的一個核心部分。 -
A clause is formalized as a relational algebra expression and evaluated by employment of relational algebra operations. 3. the proof theory based on xml is presented
提出了利用關系代數運算實現xml查詢子句求值的方法，並證明了該方法的正確性。 -
This course is designed to introduce graduate students to the foundations of database systems, focusing on basics such as the relational algebra and data model, query optimization, query processing, and transactions
課程描述本課程設計的目的是給研究生介紹數據庫的基礎知識，關注于基礎，如關系代數和數據模型，查詢優化、查詢處理和事務。 -
At the same time, we propose a representative data model, i. e. gt data model, and its query language. theoretically, we deeply study the temporal relational algebra and sql - like language based on our ter model, laying a solid theoretic foundation for our accelerator rjf cavity design system
因此，論文提出了一個概念性數據模型，即時態實體一關系數據模型（ ter模型廠提出了一個表示性數扼模型，即gt數據模型及其查詢語言。 -
In order to unify stored data - mining results in pattern warehouse, the author probes intensively into the storage methods of data - mining results ( association rules, classification rules, sequential patterns ). it proposes the storage methods to use the relational algebra to describe. this realizes consistent storage of data - mining results in relational database
為使數據挖掘結果能統一存儲在模式庫中，作者對關聯規則、分類規則和序列模式挖掘結果的存儲方法進行了深入的研究，提出了數據挖掘結果模式的存儲方法，並用關系代數進行了描述，在關系數據庫中實現了多種數據挖掘結果模式的統一存儲。
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