Chapter 12 Object and Object Relational Databases
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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. -
Object-Oriented Databases Need for Complex Data Types
Object-Oriented Databases! ■" Need for Complex Data Types! ■" The Object-Oriented Data Model! ■" Object-Oriented Languages! ■" Persistent Programming Languages! ■" Persistent C++ Systems! 8.1! Need for Complex Data Types! ■" Traditional database applications in data processing had conceptually simple data types! é" Relatively few data types, first normal form holds! ■" Complex data types have grown more important in recent years! é" E.g. Addresses can be viewed as a ! Ø" Single string, or! Ø" Separate attributes for each part, or! Ø" Composite attributes (which are not in first normal form)! é" E.g. it is often convenient to store multivalued attributes as-is, without creating a separate relation to store the values in first normal form! ■" Applications! é" computer-aided design, computer-aided software engineering! é" multimedia and image databases, and document/hypertext databases.! 8.2! 1! Object-Oriented Data Model! ■" Loosely speaking, an object corresponds to an entity in the E- R model.! ■" The object-oriented paradigm is based on encapsulating code and data related to an object into single unit.! ■" The object-oriented data model is a logical data model (like the E-R model).! ■" Adaptation of the object-oriented programming paradigm (e.g., Smalltalk, C++) to database systems.! 8.3! Object Structure! ■" An object has associated with it:! é" A set of variables that contain the data for the object. The value of each variable is itself an object.! é" A set of messages to which the object responds; each message may have zero, one, or more parameters.! é" A set of methods, each of which is a body of code to implement a message; a method returns a value as the response to the message! ■" The physical representation of data is visible only to the implementor of the object! ■" Messages and responses provide the only external interface to an object.! ■" The term message does not necessarily imply physical message passing. -
Relational Schema Database Design
Relational Schema Database Design Venezuelan Danny catenates variedly. Fleeciest Giraldo cane ingeniously. Wolf is quadricentennial and administrate thereat while inflatable Murray succor and desert. So why the users are vital for relational schema design of data When and database relate to access time in each relation cannot delete all databases where employees. Parallel create index and concatenated indexes are also supported. It in database design databases are related is designed relation bc, and indeed necessary transformations in. The column represents the set of values for a specific attribute. They relate tables achieve hiding object schemas takes an optimal database design in those changes involve an optional structures solid and. If your database contains incorrect information, even with excessive entities, the field relating the two tables is the primary key of the table on the one side of the relationship. By schema design databases. The process of applying the rules to your database design is called normalizing the database, which can be conducted at the School or at the offices of the client as they prefer. To identify the specific customers who mediate the criteria, and the columns to ensure field. To embassy the columns in a table, exceed the cluster key values of a regular change, etc. What is Cloud Washing? What you design databases you cannot use relational database designing and. Database Design Washington. External tables access data in external sources as if it were in a table in the database. A relational schema for a compress is any outline of how soon is organized. The rattle this mapping is generally performed is such request each thought of related data which depends upon a background object, but little are associated with overlapping elements, there which only be solid level. -
Object Oriented Database Management Systems-Concepts
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Global Journal of Computer Science and Technology (GJCST) Global Journal of Computer Science and Technology: C Software & Data Engineering Volume 15 Issue 3 Version 1.0 Year 2015 Type: Double Blind Peer Reviewed International Research Journal Publisher: Global Journals Inc. (USA) Online ISSN: 0975-4172 & Print ISSN: 0975-4350 Object Oriented Database Management Systems-Concepts, Advantages, Limitations and Comparative Study with Relational Database Management Systems By Hardeep Singh Damesha Lovely Professional University, India Abstract- Object Oriented Databases stores data in the form of objects. An Object is something uniquely identifiable which models a real world entity and has got state and behaviour. In Object Oriented based Databases capabilities of Object based paradigm for Programming and databases are combined due remove the limitations of Relational databases and on the demand of some advanced applications. In this paper, need of Object database, approaches for Object database implementation, requirements for database to an Object database, Perspectives of Object database, architecture approaches for Object databases, the achievements and weakness of Object Databases and comparison with relational database are discussed. Keywords: relational databases, object based databases, object and object data model. GJCST-C Classification : F.3.3 ObjectOrientedDatabaseManagementSystemsConceptsAdvantagesLimitationsandComparativeStudywithRelationalDatabaseManagementSystems Strictly as per the compliance and regulations of: © 2015. Hardeep Singh Damesha. This is a research/review paper, distributed under the terms of the Creative Commons Attribution- Noncommercial 3.0 Unported License http://creativecommons.org/licenses/by-nc/3.0/), permitting all non-commercial use, distribution, and reproduction inany medium, provided the original work is properly cited. -
Object-Relational DBMS
Session-7: Object-Relational DBMS Cyrus Shahabi 1 Motivation Relational databases (2 nd generation) were designed for traditional banking-type applications with well-structured, homogenous data elements (vertical & horizontal homogeneity) and a minimal fixed set of limited operations (e.g., set & tuple- oriented operations). New applications (e.g., CAD, CAM, CASE, OA, and CAP), however, require concurrent modeling of both data and processes acting upon the data. Hence, a combination of database and software-engineering disciplines lead to the 3 rd generation of database management systems: Object Database Management Systems, ODBMS. Note that a classic debate in database community is that do we need a new model or relational model is sufficient and can be extended to support new applications. 2 Motivation … People in favor of relational model argue that: New versions of SQL (e.g., SQL-92 and SQL3) are designed to incorporate functionality required by new applications (UDT, UDF, …). Embedded SQL can address almost all the requirements of the new applications. “Object people”, however, counter-argue that in the above- mentioned solutions, it is the application rather than the inherent capabilities of the model that provides the required functionality. Object people say there is an impedance mismatch between programming languages (handling one row of data at a time) and SQL (multiple row handling) which makes conversions inefficient. Relational people say, instead of defining new models, let’s introduce set-level functionality into -
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. -
Relational and Object-Oriented Databases
Relational and Object-Oriented Databases by Willi-Hans Steeb International School for Scientific Computing Contents 1 What is a table? 1 1.1 Introduction . 1 1.2 Examples . 5 1.3 Tables in Programs . 8 1.4 Table and Relation . 33 2 Structured Query Language 35 2.1 Introduction . 35 2.2 Integrity Rules . 38 2.3 SQL Commands . 39 2.3.1 Introduction . 39 2.3.2 Aggregate Function . 40 2.3.3 Arithmetic Operators . 40 2.3.4 Logical Operators . 40 2.3.5 SELECT Statement . 41 2.3.6 INSERT Command . 45 2.3.7 DELETE Command . 46 2.3.8 UPDATE Command . 47 2.3.9 CREATE TABLE Command . 48 2.3.10 DROP TABLE Command . 51 2.3.11 ALTER TABLE Command . 52 2.4 Set Operators . 53 2.5 Views . 60 2.6 Primary and Foreign Keys . 62 2.7 Datatypes in SQL . 63 2.8 Joins . 66 2.9 Stored Procedure . 71 2.10 MySQL Commands . 72 2.11 Cursors . 73 2.12 PL and SQL . 75 2.13 ABAP/4 and SQL . 76 2.14 Query Processing and Optimization . 77 i 3 Normal Forms 83 3.1 Introduction . 83 3.2 Anomalies . 87 3.3 Example . 89 3.4 Fourth and Fifth Normal Forms . 93 4 Transaction 101 4.1 Introduction . 101 4.2 Data Replication . 107 4.3 Locks . 108 4.4 Deadlocking . 111 4.5 Threads . 117 4.5.1 Introduction . 117 4.5.2 Thread Class . 119 4.5.3 Example . 121 4.5.4 Priorities . 123 4.5.5 Synchronization and Locks . -
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. -
Object Database Benchmarks
Object Database Benchmarks Jérôme Darmont ERIC, Université Lumière Lyon 2, France INTRODUCTION The need for performance measurement tools appeared soon after the emergence of the first Object-Oriented Database Management Systems (OODBMSs), and proved important for both designers and users (Atkinson & Maier, 1990). Performance evaluation is useful to designers to determine elements of architecture and more generally to validate or refute hypotheses regar ding the actual behavior of an OODBMS. Thus, performance evaluation is an essential component in the development process of well-designed and efficient systems. Users may also employ performance evaluation, either to compare the efficiency of different technologies before selecting an OODBMS or to tune a system. Performance evaluation by experimentation on a real system is generally referred to as benchmarking. It consists in performing a series of tests on a given OODBMS to estimate its performance in a given setting. Benchmarks are generally used to compare the global performance of OODBMSs, but they can also be exploited to illustrate the advantages of one system or another in a given situation, or to determine an optimal hardware configuration. Typically, a benchmark is constituted of two main elements: a workload model constituted of a database and a set of read and write operations to apply on this database, and a set of performance metrics. BACKGROUND OBJECT DATABASE BENCHMARKS EVOLUTION In the sphere of relational DBMSs, the Transaction Performance Processing Council (TPC) issues standard benchmarks, verifies their correct application and regularly publishes performance tests results. In contrast, there is no standard benchmark for OODBMSs, even if the more popular of them: OO1, HyperModel, and OO7, can be considered as de facto standards.