作者: 自負(fù)的人 時(shí)間: 2025-3-21 23:53
Textbook 2000nto classical database models and languages such as relational, hierarchical, and network models and languages, and also into object-oriented models. The book is of interest for all database theoreticians as well as practitioners who are provided with the relevant foundations of database modeling.作者: Proponent 時(shí)間: 2025-3-22 00:42
https://doi.org/10.1007/978-3-531-90283-8th the use of default assumptions in the case of missing specifications). This points directly to a principal advantage of ER modeling: Modeling a type as a complete item leads to a more complete specification. However for this reason, classical modeling methodologies cannot be applied in the same manner.作者: 國(guó)家明智 時(shí)間: 2025-3-22 06:05 作者: Moderate 時(shí)間: 2025-3-22 10:48
ng of database and information systems applications.IncludesDatabase technology and entity-relationship (ER) modeling have meanwhile reached the level of an established technology. This book presents the achievements of research in this field in a comprehensive survey. It deals with the entity-relat作者: 子女 時(shí)間: 2025-3-22 13:22
Digitales Nomadentum als Lebensstilodologies and database design strategies. We compare this theory with classical approaches developed mainly for relational database models. Furthermore, we discuss how information engineering can be supported by tool boxes.作者: 子女 時(shí)間: 2025-3-22 17:05
https://doi.org/10.1007/978-3-531-92516-5the examples discussed above. The translation approach introduced below summarizes, generalizes and extends the approaches presented in [BCN92, FaV94, MaR92a, MaR96, Run94, Sto91] and [AzP86, BDG83, Che76, DoC83, DuA83, E1N89, JaN83, Lin85b, MaM90, MMR85, MaS89a, MaS89b, SpC89].作者: 敬禮 時(shí)間: 2025-3-23 01:07 作者: Allure 時(shí)間: 2025-3-23 01:42
https://doi.org/10.1057/9781137272621 the limitation to 1-n-binary relationship types (functions), led to frightening modeling. Extensions of the model can be safe or unsafe. In Sect. 4 we show how to extend the original ER model to a safe, well-founded and practicable ER model. Due to the problems with pointer or reference semantics we only use set semantics.作者: aspect 時(shí)間: 2025-3-23 05:45
Ursula Mense-Petermann,Gabriele Wagnertroduced so far lack formal semantics. The languages based on data structures are similar to network languages [Sub87] and based on a calculus. [GoH88, HoG88] use a formal definition for semantics of ER types. Different ER languages such as DESPATH, ERROL, ER-LANG (IBM), GDL, GOR-DAS, GQL/ER, LSL, NETUL, SQL/ER have been proposed.作者: depreciate 時(shí)間: 2025-3-23 10:36 作者: Ingest 時(shí)間: 2025-3-23 16:34
Operations,troduced so far lack formal semantics. The languages based on data structures are similar to network languages [Sub87] and based on a calculus. [GoH88, HoG88] use a formal definition for semantics of ER types. Different ER languages such as DESPATH, ERROL, ER-LANG (IBM), GDL, GOR-DAS, GQL/ER, LSL, NETUL, SQL/ER have been proposed.作者: Kidnap 時(shí)間: 2025-3-23 19:05
Applying the Theory,algebra approach [GKS91]. For this model a simple design methodology is available. Furthermore, the HERM approach can be downloaded to an intelligent user interface for a variety of database systems and can be used in federated database systems. Based on these achievements, a sound and powerful design methodology can be developed.作者: 珠寶 時(shí)間: 2025-3-24 01:39
The Database Design Process in HERM,odologies and database design strategies. We compare this theory with classical approaches developed mainly for relational database models. Furthermore, we discuss how information engineering can be supported by tool boxes.作者: MELD 時(shí)間: 2025-3-24 03:28
The Translation of HERM Schemes,the examples discussed above. The translation approach introduced below summarizes, generalizes and extends the approaches presented in [BCN92, FaV94, MaR92a, MaR96, Run94, Sto91] and [AzP86, BDG83, Che76, DoC83, DuA83, E1N89, JaN83, Lin85b, MaM90, MMR85, MaS89a, MaS89b, SpC89].作者: 透明 時(shí)間: 2025-3-24 10:06
Margit Fauser,Eveline Reisenaueralgebra approach [GKS91]. For this model a simple design methodology is available. Furthermore, the HERM approach can be downloaded to an intelligent user interface for a variety of database systems and can be used in federated database systems. Based on these achievements, a sound and powerful design methodology can be developed.作者: 修正案 時(shí)間: 2025-3-24 12:04 作者: CLIFF 時(shí)間: 2025-3-24 15:02 作者: FLASK 時(shí)間: 2025-3-24 19:08
Other Movements and Organizations, (or for a database paradigm) so that it contains all the information required by the user and for the efficient behavior of the whole information system for all users and with application processes and user interaction.作者: Kindle 時(shí)間: 2025-3-25 02:23
,The Home Elsewhere: Simone Lazaroo’s ,stem (or for a database paradigm) so that it contains all the information required by the user and for the efficient behavior of the whole information system for all users and with application processes and user interaction.作者: 錫箔紙 時(shí)間: 2025-3-25 03:39
https://doi.org/10.1057/9781137272621derstand why it is necessary to extend the model, we will briefly discuss the original ER model first published by Chen [Che76]. It has been extended or restricted by several authors. The number of extensions can be estimated to be more than 80. Further, the model has been used with different semant作者: pulmonary-edema 時(shí)間: 2025-3-25 10:42 作者: senile-dementia 時(shí)間: 2025-3-25 14:49
Ursula Mense-Petermann,Gabriele Wagneruct and difference. Additionally [PRY89] uses relationship join, product, reduction, compression, renaming, simplification and the value selection operators .. and ... These operations are too powerful for generation of generic queries. A similar system is used in [CEC85, MMT86, ZhM83]. As far as we作者: 付出 時(shí)間: 2025-3-25 15:58
Margit Fauser,Eveline Reisenaueraradigms in a simple manner thus making them understandable and usable, even for beginners. The model is theoretically based, as we have demonstrated in the case of integrity constraints. In the same way the semantics of operations and the behavior of the database can be expressed using an evolving 作者: Inkling 時(shí)間: 2025-3-25 20:31 作者: 使成核 時(shí)間: 2025-3-26 02:08 作者: folliculitis 時(shí)間: 2025-3-26 06:34
Other Movements and Organizations, (or for a database paradigm) so that it contains all the information required by the user and for the efficient behavior of the whole information system for all users and with application processes and user interaction.作者: 諷刺 時(shí)間: 2025-3-26 11:23 作者: arboretum 時(shí)間: 2025-3-26 14:06
Introduction, (or for a database paradigm) so that it contains all the information required by the user and for the efficient behavior of the whole information system for all users and with application processes and user interaction.作者: 即席演說(shuō) 時(shí)間: 2025-3-26 19:26 作者: GRATE 時(shí)間: 2025-3-26 21:26
Transnationale Altersmigration in EuropaAt this point we will introduce the structural part of the higher-order entity-relationship model (HERM). In this section, it will be shown that a . exists for this model. Furthermore, there are several . to the HERM approach:作者: Blanch 時(shí)間: 2025-3-27 03:07
Definitionen und statistische Konzepte,Database behavior manifests itself in the evolution of the database contents with time. Evolution can be described by database sequences. In this case, behavior corresponds more to transaction time than to deterministic interstate time. The last approach is defined by basic operations. Transactions enable encapsulation of operations.作者: Temporal-Lobe 時(shí)間: 2025-3-27 08:51
https://doi.org/10.1007/978-3-322-81157-8We have presented an extended ER model together with relevant theoretical investigations. Although the extensions are simple they are very useful for practical database modeling. We have developed some theoretical fundamentals and illustrated that this model has a sound, well-founded theory similar to that of the relational model.作者: Delectable 時(shí)間: 2025-3-27 13:24
Extending the Entity-Relationship Model,At this point we will introduce the structural part of the higher-order entity-relationship model (HERM). In this section, it will be shown that a . exists for this model. Furthermore, there are several . to the HERM approach:作者: hemorrhage 時(shí)間: 2025-3-27 15:07
Behavior Modeling,Database behavior manifests itself in the evolution of the database contents with time. Evolution can be described by database sequences. In this case, behavior corresponds more to transaction time than to deterministic interstate time. The last approach is defined by basic operations. Transactions enable encapsulation of operations.作者: NEX 時(shí)間: 2025-3-27 19:41
Open Problems,We have presented an extended ER model together with relevant theoretical investigations. Although the extensions are simple they are very useful for practical database modeling. We have developed some theoretical fundamentals and illustrated that this model has a sound, well-founded theory similar to that of the relational model.作者: aristocracy 時(shí)間: 2025-3-27 23:12
978-3-642-08480-5Springer-Verlag Berlin Heidelberg 2000作者: corpus-callosum 時(shí)間: 2025-3-28 03:44 作者: photopsia 時(shí)間: 2025-3-28 07:01 作者: 合群 時(shí)間: 2025-3-28 11:15
The Database Design Process,stem (or for a database paradigm) so that it contains all the information required by the user and for the efficient behavior of the whole information system for all users and with application processes and user interaction.作者: FELON 時(shí)間: 2025-3-28 16:51 作者: 軍械庫(kù) 時(shí)間: 2025-3-28 20:58
Integrity Constraints,cs, which is rather simple compared with other database models such as the relational model, the network model or the hierarchical model. One lesson learned in the relational model is that it is not necessary to develop the theory of dependency classes and then apply it to the defined types. Instead作者: 瑣碎 時(shí)間: 2025-3-29 01:32
Operations,uct and difference. Additionally [PRY89] uses relationship join, product, reduction, compression, renaming, simplification and the value selection operators .. and ... These operations are too powerful for generation of generic queries. A similar system is used in [CEC85, MMT86, ZhM83]. As far as we作者: 開(kāi)始沒(méi)有 時(shí)間: 2025-3-29 03:23
Applying the Theory,aradigms in a simple manner thus making them understandable and usable, even for beginners. The model is theoretically based, as we have demonstrated in the case of integrity constraints. In the same way the semantics of operations and the behavior of the database can be expressed using an evolving 作者: 補(bǔ)角 時(shí)間: 2025-3-29 08:56 作者: invulnerable 時(shí)間: 2025-3-29 14:49 作者: SEVER 時(shí)間: 2025-3-29 17:12 作者: 構(gòu)成 時(shí)間: 2025-3-29 23:02 作者: Decimate 時(shí)間: 2025-3-30 02:17
