Relational Schema Database Design
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Not ACID, Not BASE, but SALT a Transaction Processing Perspective on Blockchains
Not ACID, not BASE, but SALT A Transaction Processing Perspective on Blockchains Stefan Tai, Jacob Eberhardt and Markus Klems Information Systems Engineering, Technische Universitat¨ Berlin fst, je, [email protected] Keywords: SALT, blockchain, decentralized, ACID, BASE, transaction processing Abstract: Traditional ACID transactions, typically supported by relational database management systems, emphasize database consistency. BASE provides a model that trades some consistency for availability, and is typically favored by cloud systems and NoSQL data stores. With the increasing popularity of blockchain technology, another alternative to both ACID and BASE is introduced: SALT. In this keynote paper, we present SALT as a model to explain blockchains and their use in application architecture. We take both, a transaction and a transaction processing systems perspective on the SALT model. From a transactions perspective, SALT is about Sequential, Agreed-on, Ledgered, and Tamper-resistant transaction processing. From a systems perspec- tive, SALT is about decentralized transaction processing systems being Symmetric, Admin-free, Ledgered and Time-consensual. We discuss the importance of these dual perspectives, both, when comparing SALT with ACID and BASE, and when engineering blockchain-based applications. We expect the next-generation of decentralized transactional applications to leverage combinations of all three transaction models. 1 INTRODUCTION against. Using the admittedly contrived acronym of SALT, we characterize blockchain-based transactions There is a common belief that blockchains have the – from a transactions perspective – as Sequential, potential to fundamentally disrupt entire industries. Agreed, Ledgered, and Tamper-resistant, and – from Whether we are talking about financial services, the a systems perspective – as Symmetric, Admin-free, sharing economy, the Internet of Things, or future en- Ledgered, and Time-consensual. -
The Relational Data Model and Relational Database Constraints
chapter 33 The Relational Data Model and Relational Database Constraints his chapter opens Part 2 of the book, which covers Trelational databases. The relational data model was first introduced by Ted Codd of IBM Research in 1970 in a classic paper (Codd 1970), and it attracted immediate attention due to its simplicity and mathematical foundation. The model uses the concept of a mathematical relation—which looks somewhat like a table of values—as its basic building block, and has its theoretical basis in set theory and first-order predicate logic. In this chapter we discuss the basic characteristics of the model and its constraints. The first commercial implementations of the relational model became available in the early 1980s, such as the SQL/DS system on the MVS operating system by IBM and the Oracle DBMS. Since then, the model has been implemented in a large num- ber of commercial systems. Current popular relational DBMSs (RDBMSs) include DB2 and Informix Dynamic Server (from IBM), Oracle and Rdb (from Oracle), Sybase DBMS (from Sybase) and SQLServer and Access (from Microsoft). In addi- tion, several open source systems, such as MySQL and PostgreSQL, are available. Because of the importance of the relational model, all of Part 2 is devoted to this model and some of the languages associated with it. In Chapters 4 and 5, we describe the SQL query language, which is the standard for commercial relational DBMSs. Chapter 6 covers the operations of the relational algebra and introduces the relational calculus—these are two formal languages associated with the relational model. -
Relational Database Fundamentals
05_04652x ch01.qxp 7/10/06 1:45 PM Page 7 Chapter 1 Relational Database Fundamentals In This Chapter ᮣ Organizing information ᮣ Defining database ᮣ Defining DBMS ᮣ Comparing database models ᮣ Defining relational database ᮣ Considering the challenges of database design QL (pronounced ess-que-ell, not see’qwl) is an industry-standard language Sspecifically designed to enable people to create databases, add new data to databases, maintain the data, and retrieve selected parts of the data. Various kinds of databases exist, each adhering to a different conceptual model. SQL was originally developed to operate on data in databases that follow the relational model. Recently, the international SQL standard has incorporated part of the object model, resulting in hybrid structures called object-relational databases. In this chapter, I discuss data storage, devote a section to how the relational model compares with other major models, and provide a look at the important features of relational databases. Before I talk about SQL, however, I need to nail down what I mean by the term database. Its meaning has changed as computers have changed the way people record and maintain information. COPYRIGHTED MATERIAL Keeping Track of Things Today, people use computers to perform many tasks formerly done with other tools. Computers have replaced typewriters for creating and modifying documents. They’ve surpassed electromechanical calculators as the best way to do math. They’ve also replaced millions of pieces of paper, file folders, and file cabinets as the principal storage medium for important information. Compared to those old tools, of course, computers do much more, much faster — and with greater accuracy. -
Accessing a Relational Database Through an Object-Oriented Database Interface (Extended Abstract)
Accessing a Relational Database through an Object-Oriented Database Interface (extended abstract) J. A. Orenstein D. N. Kamber Object Design, Inc. Credit Suisse [email protected] [email protected] Object-oriented database systems (ODBs) are Typically, their goal is not to migrate data from designedfor use in applicationscharacterized by complex relational databases into object-oriented databases. data models, clean integration with the host ODBs and RDBs are likely to have different programming language, and a need for extremely fast performance characteristics for some time, and it is creation, traversal, and update of networks of objects. therefore unlikely that one kind of systemcan displace Theseapplications are typically written in C or C++, and the other. Instead,the goal is to provide accessto legacy the problem of how to store the networks of objects, and databasesthrough object-orientedinterfaces. update them atomically has been difficult in practice. For this reason, we designed and developed, in Relational databasesystems (RDBs) tend to be a poor fit conjunction,with the Santa Teresa Labs of IBM, the for these applications because they are designed for ObjectStoreGateway, a systemwhich providesaccess to applications with different performance requirements. relationaldatabasesthrough the ObjectStoreapplication ODBs are designedto meet theserequirements and have programming interface (API). ObjectStore queries, proven more successful in pioviding”persistence for collectionand cursor operationsare translatedinto SQL. applicationssuch as ECAD and MCAD.’ The tuple streamsresulting from execution of the SQL Interest in ODBs has-spread be$ond the CAD query are turned into objects;these objects may be either communities, to areas such as finance and transient, or persistent, stored in an ObjectStore telecommunications. -
8 the Relational Data Model
CHAPTER 8 ✦ ✦ ✦ ✦ The Relational Data Model One of the most important applications for computers is storing and managing information. The manner in which information is organized can have a profound effect on how easy it is to access and manage. Perhaps the simplest but most versatile way to organize information is to store it in tables. The relational model is centered on this idea: the organization of data into collections of two-dimensional tables called “relations.” We can also think of the relational model as a generalization of the set data model that we discussed in Chapter 7, extending binary relations to relations of arbitrary arity. Originally, the relational data model was developed for databases — that is, Database information stored over a long period of time in a computer system — and for database management systems, the software that allows people to store, access, and modify this information. Databases still provide us with important motivation for understanding the relational data model. They are found today not only in their original, large-scale applications such as airline reservation systems or banking sys- tems, but in desktop computers handling individual activities such as maintaining expense records, homework grades, and many other uses. Other kinds of software besides database systems can make good use of tables of information as well, and the relational data model helps us design these tables and develop the data structures that we need to access them efficiently. For example, such tables are used by compilers to store information about the variables used in the program, keeping track of their data type and of the functions for which they are defined. -
DBMS Keys Mahmoud El-Haj 13/01/2020 The
DBMS Keys Mahmoud El-Haj 13/01/2020 The following is to help you understand the DBMS Keys mentioned in the 2nd lecture (2. Relational Model) Why do we need keys: • Keys are the essential elements of any relational database. • Keys are used to identify tuples in a relation R. • Keys are also used to establish the relationship among the tables in a schema. Type of keys discussed below: Superkey, Candidate Key, Primary Key (for Foreign Key please refer to the lecture slides (2. Relational Model). • Superkey (SK) of a relation R: o Is a set of attributes SK of R with the following condition: . No two tuples in any valid relation state r(R) will have the same value for SK • That is, for any distinct tuples t1 and t2 in r(R), t1[SK] ≠ t2[SK] o Every relation has at least one default superkey: the set of all its attributes o Basically superkey is nothing but a key. It is a super set of keys where all possible keys are included (see example below). o An attribute or a set of attributes that can be used to identify a tuple (row) of data in a Relation (table) is a Superkey. • Candidate Key of R (all superkeys that can be candidate keys): o A "minimal" superkey o That is, a (candidate) key is a superkey K such that removal of any attribute from K results in a set of attributes that IS NOT a superkey (does not possess the superkey uniqueness property) (see example below). o A Candidate Key is a Superkey but not necessarily vice versa o Candidate Key: Are keys which can be a primary key. -
A Methodology for Evaluating Relational and Nosql Databases for Small-Scale Storage and Retrieval
Air Force Institute of Technology AFIT Scholar Theses and Dissertations Student Graduate Works 9-1-2018 A Methodology for Evaluating Relational and NoSQL Databases for Small-Scale Storage and Retrieval Ryan D. Engle Follow this and additional works at: https://scholar.afit.edu/etd Part of the Databases and Information Systems Commons Recommended Citation Engle, Ryan D., "A Methodology for Evaluating Relational and NoSQL Databases for Small-Scale Storage and Retrieval" (2018). Theses and Dissertations. 1947. https://scholar.afit.edu/etd/1947 This Dissertation is brought to you for free and open access by the Student Graduate Works at AFIT Scholar. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of AFIT Scholar. For more information, please contact [email protected]. A METHODOLOGY FOR EVALUATING RELATIONAL AND NOSQL DATABASES FOR SMALL-SCALE STORAGE AND RETRIEVAL DISSERTATION Ryan D. L. Engle, Major, USAF AFIT-ENV-DS-18-S-047 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio DISTRIBUTION STATEMENT A. Approved for public release: distribution unlimited. AFIT-ENV-DS-18-S-047 The views expressed in this paper are those of the author and do not reflect official policy or position of the United States Air Force, Department of Defense, or the U.S. Government. This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States. i AFIT-ENV-DS-18-S-047 A METHODOLOGY FOR EVALUATING RELATIONAL AND NOSQL DATABASES FOR SMALL-SCALE STORAGE AND RETRIEVAL DISSERTATION Presented to the Faculty Department of Systems and Engineering Management Graduate School of Engineering and Management Air Force Institute of Technology Air University Air Education and Training Command In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Ryan D. -
The Relational Model
The Relational Model Read Text Chapter 3 Laks VS Lakshmanan; Based on Ramakrishnan & Gehrke, DB Management Systems Learning Goals given an ER model of an application, design a minimum number of correct tables that capture the information in it given an ER model with inheritance relations, weak entities and aggregations, design the right tables for it given a table design, create correct tables for this design in SQL, including primary and foreign key constraints compare different table designs for the same problem, identify errors and provide corrections Unit 3 2 Historical Perspective Introduced by Edgar Codd (IBM) in 1970 Most widely used model today. Vendors: IBM, Informix, Microsoft, Oracle, Sybase, etc. “Legacy systems” are usually hierarchical or network models (i.e., not relational) e.g., IMS, IDMS, … Unit 3 3 Historical Perspective Competitor: object-oriented model ObjectStore, Versant, Ontos A synthesis emerging: object-relational model o Informix Universal Server, UniSQL, O2, Oracle, DB2 Recent competitor: XML data model In all cases, relational systems have been extended to support additional features, e.g., objects, XML, text, images, … Unit 3 4 Main Characteristics of the Relational Model Exceedingly simple to understand All kinds of data abstracted and represented as a table Simple query language separate from application language Lots of bells and whistles to do complicated things Unit 3 5 Structure of Relational Databases Relational database: a set of relations Relation: made up of 2 parts: Schema : specifies name of relation, plus name and domain (type) of each field (or column or attribute). o e.g., Student (sid: string, name: string, address: string, phone: string, major: string). -
The Relational Model
The Relational Model Watch video: https://youtu.be/gcYKGV-QKB0?t=5m15s Topics List • Relational Model Terminology • Properties of Relations • Relational Keys • Integrity Constraints • Views Relational Model Terminology • A relation is a table with columns and rows. • Only applies to logical structure of the database, not the physical structure. • Attribute is a named column of a relation. • Domain is the set of allowable values for one or more attributes. Relational Model Terminology • Tuple is a row of a relation. • Degree is the number of attributes in a relation. • Cardinality is the number of tuples in a relation. • Relational Database is a collection of normalised relations with distinct relation names. Instances of Branch and Staff Relations Examples of Attribute Domains Alternative Terminology for Relational Model Topics List • Relational Model Terminology • Properties of Relations • Relational Keys • Integrity Constraints • Views Properties of Relations • Relation name is distinct from all other relation names in relational schema. • Each cell of relation contains exactly one atomic (single) value. • Each attribute has a distinct name. • Values of an attribute are all from the same domain. Properties of Relations • Each tuple is distinct; there are no duplicate tuples. • Order of attributes has no significance. • Order of tuples has no significance, theoretically. Topics List • Relational Model Terminology • Properties of Relations • Relational Keys • Integrity Constraints • Views Relational Keys • Superkey • Super key stands for superset of a key. A Super Key is a set of one or more attributes that are taken collectively and can identify all other attributes uniquely. • An attribute, or set of attributes, that uniquely identifies a tuple within a relation. -
Performance Analysis of Nosql and Relational Databases with Couchdb and Mysql for Application’S Data Storage
applied sciences Article Performance Analysis of NoSQL and Relational Databases with CouchDB and MySQL for Application’s Data Storage Cornelia A. Gy˝orödi 1,* , Diana V. Dum¸se-Burescu 2, Doina R. Zmaranda 1 , Robert ¸S.Gy˝orödi 1 , Gianina A. Gabor 1 and George D. Pecherle 1 1 Department of Computer Science and Information Technology, University of Oradea, 410087 Oradea, Romania; [email protected] (D.R.Z.); [email protected] (R.¸S.G.); [email protected] (G.A.G.); [email protected] (G.D.P.) 2 Faculty of Electrical Engineering and Information Technology, Department of Computer Science and Information Technology, University of Oradea, 410087 Oradea, Romania; [email protected] * Correspondence: [email protected] Received: 6 November 2020; Accepted: 25 November 2020; Published: 28 November 2020 Abstract: In the current context of emerging several types of database systems (relational and non-relational), choosing the type and database system for storing large amounts of data in today’s big data applications has become an important challenge. In this paper, we aimed to provide a comparative evaluation of two popular open-source database management systems (DBMSs): MySQL as a relational DBMS and, more recently, as a non-relational DBMS, and CouchDB as a non-relational DBMS. This comparison was based on performance evaluation of CRUD (CREATE, READ, UPDATE, DELETE) operations for different amounts of data to show how these two databases could be modeled and used in an application and highlight the differences in the response time and complexity. The main objective of the paper was to make a comparative analysis of the impact that each specific DBMS has on application performance when carrying out CRUD requests. -
Translation of ER-Diagram Into Relational Schema
TranslationTranslation ofof ERER --diagramdiagram intointo RelationalRelational SchemaSchema Dr. Sunnie S. Chung CIS430/530 LearningLearning ObjectivesObjectives Define each of the following database terms Relation Primary key Foreign key Referential integrity Field Data type Null value Discuss the role of designing databases in the analysis and design of an information system Learn how to transform an entity-relationship (ER) 9.29.2 Diagram into an equivalent set of well-structured relations 2 3 9.49.4 4 5 ProcessProcess ofof DatabaseDatabase DesignDesign • Logical Design – Based upon the conceptual data model – Four key steps 1. Develop a logical data model for each known user interface for the application using normalization principles. 2. Combine normalized data requirements from all user interfaces into one consolidated logical database model 3. Translate the conceptual E-R data model for the application into normalized data requirements 4. Compare the consolidated logical database design with the 9.69.6 translated E-R model and produce one final logical database model for the application 6 9.79.7 7 RelationalRelational DatabaseDatabase ModelModel • Data represented as a set of related tables or relations • Relation – A named, two-dimensional table of data. Each relation consists of a set of named columns and an arbitrary number of unnamed rows – Properties • Entries in cells are simple • Entries in columns are from the same set of values • Each row is unique • The sequence of columns can be interchanged without changing the meaning or use of the relation • The rows may be interchanged or stored in any 9.89.8 sequence 8 RelationalRelational DatabaseDatabase ModelModel • Well-Structured Relation – A relation that contains a minimum amount of redundancy and allows users to insert, modify and delete the rows without errors or inconsistencies 9.99.9 9 TransformingTransforming EE --RR DiagramsDiagrams intointo RelationsRelations • It is useful to transform the conceptual data model into a set of normalized relations • Steps 1. -
Introduction and Data Models
NoSQL systems: introduction and data models Riccardo Torlone Università Roma Tre Leveraging the NoSQL boom 2 CREDITS: Jimmy Lin (University of Maryland) Why NoSQL? In the last fifty years relational databases have been the default choice for serious data storage. An architect starting a new project: your only choice is likely to be which relational database to use. often not even that, if your company has a dominant vendor. In the past, other proposals for database technology: deductive databases in the 1980’s object databases in the 1990’s XML databases in the 2000’s these alternatives never got anywhere. 3 CREDITS: Jimmy Lin (University of Maryland) The Value of Relational Databases Effective and efficient management of persistent data Concurrency control Data integration A standard data model A standard query language 4 CREDITS: Jimmy Lin (University of Maryland) Impedance Mismatch Difference between the persistent data model and the in-memory data structures 5 CREDITS: Jimmy Lin (University of Maryland) A proposal to solve the problem (1990s) Databases that replicate the in-memory data structures to disk Object-oriented databases! Faded into obscurity in a few years.. Solution emerged: 6 object-relational mapping frameworks CREDITS: Jimmy Lin (University of Maryland) Evolution of applications OO databases are dead. Why? SQL provides an integration mechanism between applications The database acts as an integration database Multiple applications one database 2000s: a distinct shift to application databases (SOA) Web services add more flexibility for the data structure being exchanged richer data structures to reduce the number of round trips nested records, lists, etc. usually represented in XML or JSON.