Paraconsistent database , which based on 4 - valued paraconsistent logic and relational data model , can effective manipulate two kinds of uncertain information 但以次協(xié)調(diào)邏輯與關(guān)系數(shù)據(jù)模型相結(jié)合而產(chǎn)生的次協(xié)調(diào)數(shù)據(jù)庫能夠有效地處理這兩類不確定信息。
Based on the schema of the system of information integration , the dissertation presents a common data model ( jidm ) which is a relational data model based on java 在分析了信息集成系統(tǒng)的模式結(jié)構(gòu)的基礎(chǔ)上,本文提出了一種基于java的關(guān)系數(shù)據(jù)模型( jidm )作為集成系統(tǒng)的公共數(shù)據(jù)模型。
In the database designing , this paper researches the design method , which combines expended relational data model and object ? elational data model , and realized the graph and image database 在數(shù)據(jù)庫設(shè)計中研究了使用擴(kuò)展關(guān)系數(shù)據(jù)模型和對象關(guān)系數(shù)據(jù)模型相結(jié)合的設(shè)計方法并成功實(shí)現(xiàn)圖形圖像數(shù)據(jù)庫。
Based on the reference feature of object - relational data model and the query language , the join algorithm sort - loops , probe - loops and segment - join are proposed , their performance are analyzed and compared 針對對象關(guān)系數(shù)據(jù)模型和查詢語言所支持的引用特性,設(shè)計了基于引用的連接算法sort - loops 、 probe - loops以及segment - join 。
As virtual database uses relational data model , the paper makes a special effort to discuss query rewriting technology - rewriting queries using views and its conjunctive query , containment mapping under this model 基于虛擬數(shù)據(jù)庫所采用的關(guān)系數(shù)據(jù)模型,著重探討了該模型下的查詢重寫技術(shù)? ?利用視圖重寫查詢以及基于其上的合取查詢、包含映射等問題。
Based on the work - packaging model and the database technique , the paper establishes the relational data model of the projects in civil engineering . the model will provide a method to use the computers in the projects in civil engineering 以工作包模型和數(shù)據(jù)庫技術(shù)為基礎(chǔ),建立了工程項目關(guān)系數(shù)據(jù)模型,為計算機(jī)技術(shù)在工程項目管理中的應(yīng)用提供了一定的理論基礎(chǔ)。
By analyzing the requirement of simulation and the framework , an object - relational data model which adapts to driver , vehicle , highway and environment simulation is established and the mapping principle and achieving method is studied on 從人車路與環(huán)境仿真系統(tǒng)的數(shù)據(jù)需求和體系結(jié)構(gòu)出發(fā),建立了適合人車路與環(huán)境仿真數(shù)據(jù)庫的對象?關(guān)系數(shù)據(jù)模型,研究了其映射機(jī)制和實(shí)現(xiàn)方法。
First , in this paper , a paraconsistent relational data model and its algebraic operators are introduced briefly . then , paraconsistent relational calculus based on this model is discussed and domain relational calculus for paraconsistent database is presented 本文首先簡要介紹了次協(xié)調(diào)關(guān)系數(shù)據(jù)模型及其代數(shù)運(yùn)算,并在此基礎(chǔ)上進(jìn)一步討論了次協(xié)調(diào)關(guān)系演算,提出了次協(xié)調(diào)關(guān)系上的域關(guān)系演算。
In other words , go ahead and be excited by xml s promise of a universal data transport mechanism , but keep your backend data on something designed for it , like db2 or oracle or on postgres or mysql for smaller - scale systems . the original paper introducing the relational data model is 換句話說,可以繼續(xù)使用xml并會為它所許諾的通用數(shù)據(jù)傳送機(jī)制而感到興奮,但請將您的后端數(shù)據(jù)存放在為它設(shè)計的數(shù)據(jù)庫(例如db2或oracle )上(對于規(guī)模比較小的系統(tǒng),請保存在postgres或mysql上) 。
To manage data storage , many database management system are now available , like oracle , ms sqlserver , db2 , infomix , sybase and mysql etc . these systems are all based on the theory of relational data model , and can provide us with strong functions on data storage management 在數(shù)據(jù)的存儲方面,有oracle , mssqlserver , db2 , informix , sybase , mysql等成熟的數(shù)據(jù)庫服務(wù)器產(chǎn)品提供比較完善的功能。這些建立在關(guān)系數(shù)據(jù)理論上的產(chǎn)品無論是在功能、效率還是安全等方面可以說完全能夠滿足現(xiàn)有數(shù)據(jù)存儲的需要。