Introduction to the Relational Model and SQL
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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. -
Data Analysis Expressions (DAX) in Powerpivot for Excel 2010
Data Analysis Expressions (DAX) In PowerPivot for Excel 2010 A. Table of Contents B. Executive Summary ............................................................................................................................... 3 C. Background ........................................................................................................................................... 4 1. PowerPivot ...............................................................................................................................................4 2. PowerPivot for Excel ................................................................................................................................5 3. Samples – Contoso Database ...................................................................................................................8 D. Data Analysis Expressions (DAX) – The Basics ...................................................................................... 9 1. DAX Goals .................................................................................................................................................9 2. DAX Calculations - Calculated Columns and Measures ...........................................................................9 3. DAX Syntax ............................................................................................................................................ 13 4. DAX uses PowerPivot data types ......................................................................................................... -
Database Systems Administrator FLSA: Exempt
CLOVIS UNIFIED SCHOOL DISTRICT POSITION DESCRIPTION Position: Database Systems Administrator FLSA: Exempt Department/Site: Technology Services Salary Grade: 127 Reports to/Evaluated by: Chief Technology Officer Salary Schedule: Classified Management SUMMARY Gathers requirements and provisions servers to meet the district’s need for database storage. Installs and configures SQL Server according to the specifications of outside software vendors and/or the development group. Designs and executes a security scheme to assure safety of confidential data. Implements and manages a backup and disaster recovery plan. Monitors the health and performance of database servers and database applications. Troubleshoots database application performance issues. Automates monitoring and maintenance tasks. Maintains service pack deployment and upgrades servers in consultation with the developer group and outside vendors. Deploys and schedules SQL Server Agent tasks. Implements and manages replication topologies. Designs and deploys datamarts under the supervision of the developer group. Deploys and manages cubes for SSAS implementations. DISTINGUISHING CAREER FEATURES The Database Systems Administrator is a senior level analyst position requiring specialized education and training in the field of study typically resulting in a degree. Advancement to this position would require competency in the design and administration of relational databases designated for business, enterprise, and student information. Advancement from this position is limited to supervisory management positions. ESSENTIAL DUTIES AND RESPONSIBILITIES Implements, maintains and administers all district supported versions of Microsoft SQL as well as other DBMS as needed. Responsible for database capacity planning and involvement in server capacity planning. Responsible for verification of backups and restoration of production and test databases. Designs, implements and maintains a disaster recovery plan for critical data resources. -
Rdbmss Why Use an RDBMS
RDBMSs • Relational Database Management Systems • A way of saving and accessing data on persistent (disk) storage. 51 - RDBMS CSC309 1 Why Use an RDBMS • Data Safety – data is immune to program crashes • Concurrent Access – atomic updates via transactions • Fault Tolerance – replicated dbs for instant failover on machine/disk crashes • Data Integrity – aids to keep data meaningful •Scalability – can handle small/large quantities of data in a uniform manner •Reporting – easy to write SQL programs to generate arbitrary reports 51 - RDBMS CSC309 2 1 Relational Model • First published by E.F. Codd in 1970 • A relational database consists of a collection of tables • A table consists of rows and columns • each row represents a record • each column represents an attribute of the records contained in the table 51 - RDBMS CSC309 3 RDBMS Technology • Client/Server Databases – Oracle, Sybase, MySQL, SQLServer • Personal Databases – Access • Embedded Databases –Pointbase 51 - RDBMS CSC309 4 2 Client/Server Databases client client client processes tcp/ip connections Server disk i/o server process 51 - RDBMS CSC309 5 Inside the Client Process client API application code tcp/ip db library connection to server 51 - RDBMS CSC309 6 3 Pointbase client API application code Pointbase lib. local file system 51 - RDBMS CSC309 7 Microsoft Access Access app Microsoft JET SQL DLL local file system 51 - RDBMS CSC309 8 4 APIs to RDBMSs • All are very similar • A collection of routines designed to – produce and send to the db engine an SQL statement • an original -
CHAPTER 3 - Relational Database Modeling
DATABASE SYSTEMS Introduction to Databases and Data Warehouses, Edition 2.0 CHAPTER 3 - Relational Database Modeling Copyright (c) 2020 Nenad Jukic and Prospect Press MAPPING ER DIAGRAMS INTO RELATIONAL SCHEMAS ▪ Once a conceptual ER diagram is constructed, a logical ER diagram is created, and then it is subsequently mapped into a relational schema (collection of relations) Conceptual Model Logical Model Schema Jukić, Vrbsky, Nestorov, Sharma – Database Systems Copyright (c) 2020 Nenad Jukic and Prospect Press Chapter 3 – Slide 2 INTRODUCTION ▪ Relational database model - logical database model that represents a database as a collection of related tables ▪ Relational schema - visual depiction of the relational database model – also called a logical model ▪ Most contemporary commercial DBMS software packages, are relational DBMS (RDBMS) software packages Jukić, Vrbsky, Nestorov, Sharma – Database Systems Copyright (c) 2020 Nenad Jukic and Prospect Press Chapter 3 – Slide 3 INTRODUCTION Terminology Jukić, Vrbsky, Nestorov, Sharma – Database Systems Copyright (c) 2020 Nenad Jukic and Prospect Press Chapter 3 – Slide 4 INTRODUCTION ▪ Relation - table in a relational database • A table containing rows and columns • The main construct in the relational database model • Every relation is a table, not every table is a relation Jukić, Vrbsky, Nestorov, Sharma – Database Systems Copyright (c) 2020 Nenad Jukic and Prospect Press Chapter 3 – Slide 5 INTRODUCTION ▪ Relation - table in a relational database • In order for a table to be a relation the following conditions must hold: o Within one table, each column must have a unique name. o Within one table, each row must be unique. o All values in each column must be from the same (predefined) domain. -
Relational Query Languages
Relational Query Languages Universidad de Concepcion,´ 2014 (Slides adapted from Loreto Bravo, who adapted from Werner Nutt who adapted them from Thomas Eiter and Leonid Libkin) Bases de Datos II 1 Databases A database is • a collection of structured data • along with a set of access and control mechanisms We deal with them every day: • back end of Web sites • telephone billing • bank account information • e-commerce • airline reservation systems, store inventories, library catalogs, . Relational Query Languages Bases de Datos II 2 Data Models: Ingredients • Formalisms to represent information (schemas and their instances), e.g., – relations containing tuples of values – trees with labeled nodes, where leaves contain values – collections of triples (subject, predicate, object) • Languages to query represented information, e.g., – relational algebra, first-order logic, Datalog, Datalog: – tree patterns – graph pattern expressions – SQL, XPath, SPARQL Bases de Datos II 3 • Languages to describe changes of data (updates) Relational Query Languages Questions About Data Models and Queries Given a schema S (of a fixed data model) • is a given structure (FOL interpretation, tree, triple collection) an instance of the schema S? • does S have an instance at all? Given queries Q, Q0 (over the same schema) • what are the answers of Q over a fixed instance I? • given a potential answer a, is a an answer to Q over I? • is there an instance I where Q has an answer? • do Q and Q0 return the same answers over all instances? Relational Query Languages Bases de Datos II 4 Questions About Query Languages Given query languages L, L0 • how difficult is it for queries in L – to evaluate such queries? – to check satisfiability? – to check equivalence? • for every query Q in L, is there a query Q0 in L0 that is equivalent to Q? Bases de Datos II 5 Research Questions About Databases Relational Query Languages • Incompleteness, uncertainty – How can we represent incomplete and uncertain information? – How can we query it? . -
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. -
SQL Vs Nosql: a Performance Comparison
SQL vs NoSQL: A Performance Comparison Ruihan Wang Zongyan Yang University of Rochester University of Rochester [email protected] [email protected] Abstract 2. ACID Properties and CAP Theorem We always hear some statements like ‘SQL is outdated’, 2.1. ACID Properties ‘This is the world of NoSQL’, ‘SQL is still used a lot by We need to refer the ACID properties[12]: most of companies.’ Which one is accurate? Has NoSQL completely replace SQL? Or is NoSQL just a hype? SQL Atomicity (Structured Query Language) is a standard query language A transaction is an atomic unit of processing; it should for relational database management system. The most popu- either be performed in its entirety or not performed at lar types of RDBMS(Relational Database Management Sys- all. tems) like Oracle, MySQL, SQL Server, uses SQL as their Consistency preservation standard database query language.[3] NoSQL means Not A transaction should be consistency preserving, meaning Only SQL, which is a collection of non-relational data stor- that if it is completely executed from beginning to end age systems. The important character of NoSQL is that it re- without interference from other transactions, it should laxes one or more of the ACID properties for a better perfor- take the database from one consistent state to another. mance in desired fields. Some of the NOSQL databases most Isolation companies using are Cassandra, CouchDB, Hadoop Hbase, A transaction should appear as though it is being exe- MongoDB. In this paper, we’ll outline the general differences cuted in iso- lation from other transactions, even though between the SQL and NoSQL, discuss if Relational Database many transactions are execut- ing concurrently. -
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. -
Applying the ETL Process to Blockchain Data. Prospect and Findings
information Article Applying the ETL Process to Blockchain Data. Prospect and Findings Roberta Galici 1, Laura Ordile 1, Michele Marchesi 1 , Andrea Pinna 2,* and Roberto Tonelli 1 1 Department of Mathematics and Computer Science, University of Cagliari, Via Ospedale 72, 09124 Cagliari, Italy; [email protected] (R.G.); [email protected] (L.O.); [email protected] (M.M.); [email protected] (R.T.) 2 Department of Electrical and Electronic Engineering (DIEE), University of Cagliari, Piazza D’Armi, 09100 Cagliari, Italy * Correspondence: [email protected] Received: 7 March 2020; Accepted: 7 April 2020; Published: 10 April 2020 Abstract: We present a novel strategy, based on the Extract, Transform and Load (ETL) process, to collect data from a blockchain, elaborate and make it available for further analysis. The study aims to satisfy the need for increasingly efficient data extraction strategies and effective representation methods for blockchain data. For this reason, we conceived a system to make scalable the process of blockchain data extraction and clustering, and to provide a SQL database which preserves the distinction between transaction and addresses. The proposed system satisfies the need to cluster addresses in entities, and the need to store the extracted data in a conventional database, making possible the data analysis by querying the database. In general, ETL processes allow the automation of the operation of data selection, data collection and data conditioning from a data warehouse, and produce output data in the best format for subsequent processing or for business. We focus on the Bitcoin blockchain transactions, which we organized in a relational database to distinguish between the input section and the output section of each transaction. -
Relational Algebra and SQL Relational Query Languages
Relational Algebra and SQL Chapter 5 1 Relational Query Languages • Languages for describing queries on a relational database • Structured Query Language (SQL) – Predominant application-level query language – Declarative • Relational Algebra – Intermediate language used within DBMS – Procedural 2 1 What is an Algebra? · A language based on operators and a domain of values · Operators map values taken from the domain into other domain values · Hence, an expression involving operators and arguments produces a value in the domain · When the domain is a set of all relations (and the operators are as described later), we get the relational algebra · We refer to the expression as a query and the value produced as the query result 3 Relational Algebra · Domain: set of relations · Basic operators: select, project, union, set difference, Cartesian product · Derived operators: set intersection, division, join · Procedural: Relational expression specifies query by describing an algorithm (the sequence in which operators are applied) for determining the result of an expression 4 2 The Role of Relational Algebra in a DBMS 5 Select Operator • Produce table containing subset of rows of argument table satisfying condition σ condition (relation) • Example: σ Person Hobby=‘stamps’(Person) Id Name Address Hobby Id Name Address Hobby 1123 John 123 Main stamps 1123 John 123 Main stamps 1123 John 123 Main coins 9876 Bart 5 Pine St stamps 5556 Mary 7 Lake Dr hiking 9876 Bart 5 Pine St stamps 6 3 Selection Condition • Operators: <, ≤, ≥, >, =, ≠ • Simple selection -
Reactive Relational Database Connectivity
R2DBC - Reactive Relational Database Connectivity Ben Hale<[email protected]>, Mark Paluch <[email protected]>, Greg Turnquist <[email protected]>, Jay Bryant <[email protected]> Version 0.8.0.RC1, 2019-09-26 © 2017-2019 The original authors. Copies of this document may be made for your own use and for distribution to others, provided that you do not charge any fee for such copies and further provided that each copy contains this Copyright Notice, whether distributed in print or electronically. 1 Preface License Specification: R2DBC - Reactive Relational Database Connectivity Version: 0.8.0.RC1 Status: Draft Specification Lead: Pivotal Software, Inc. Release: 2019-09-26 Copyright 2017-2019 the original author or authors. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. Foreword R2DBC brings a reactive programming API to relational data stores. The Introduction contains more details about its origins and explains its goals. This document describes the first and initial generation of R2DBC. Organization of this document This document is organized into the following parts: • Introduction • Goals • Compliance • Overview • Connections • Transactions 2 • Statements • Batches • Results • Column and Row Metadata • Exceptions • Data Types • Extensions 3 Chapter 1.