Chapter 11 Querying
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Querying Graph Databases: What Do Graph Patterns Mean?
Querying Graph Databases: What Do Graph Patterns Mean? Stephan Mennicke1( ), Jan-Christoph Kalo2, and Wolf-Tilo Balke2 1 Institut für Programmierung und Reaktive Systeme, TU Braunschweig, Germany [email protected] 2 Institut für Informationssysteme, TU Braunschweig, Germany {kalo,balke}@ifis.cs.tu-bs.de Abstract. Querying graph databases often amounts to some form of graph pattern matching. Finding (sub-)graphs isomorphic to a given graph pattern is common to many graph query languages, even though graph isomorphism often is too strict, since it requires a one-to-one cor- respondence between the nodes of the pattern and that of a match. We investigate the influence of weaker graph pattern matching relations on the respective queries they express. Thereby, these relations abstract from the concrete graph topology to different degrees. An extension of relation sequences, called failures which we borrow from studies on con- current processes, naturally expresses simple presence conditions for rela- tions and properties. This is very useful in application scenarios dealing with databases with a notion of data completeness. Furthermore, fail- ures open up the query modeling for more intricate matching relations directly incorporating concrete data values. Keywords: Graph databases · Query modeling · Pattern matching 1 Introduction Over the last years, graph databases have aroused a vivid interest in the database community. This is partly sparked by intelligent and quite robust developments in information extraction, partly due to successful standardizations for knowl- edge representation in the Semantic Web. Indeed, it is enticing to open up the abundance of unstructured information on the Web through transformation into a structured form that is usable by advanced applications. -
Delivering Oracle Compatibility
DELIVERING ORACLE COMPATIBILITY A White Paper by EnterpriseDB www.EnterpriseDB.com TABLE OF CONTENTS Executive Summary 4 Introducing EnterpriseDB Advanced Server 6 SQL Compatibility 6 PL/SQL Compatibility 9 Data Dictionary Views 11 Programming Flexibility and Drivers 12 Transfer Tools 12 Database Replication 13 Enterprise-Class Reliability and Scalability 13 Oracle-Like Tools 14 Conclusion 15 Downloading EnterpriseDB 15 EnterpriseDB EXECUTIVE SUMMARY Enterprises running Oracle® are generally interested in alternative databases for at least three reasons. First, these enterprises are experiencing budget constraints and need to lower their database Total Cost of Ownership (TCO). Second, they are trying to gain greater licensing flexibility to become more agile within the company and in the larger market. Finally, they are actively pursuing vendors who will provide superior technical support and a richer customer experience. And, subsequently, enterprises are looking for a solution that will complement their existing infrastructure and skills. The traditional database vendors have been unable to provide the combination of all three benefits. While Microsoft SQL ServerTM and IBM DB2TM may provide the flexibility and rich customer experience, they cannot significantly reduce TCO. Open source databases, on the other hand, can provide the TCO benefits and the flexibility. However, these open source databases either lack the enterprise-class features that today’s mission critical applications require or they are not equipped to provide the enterprise-class support required by these organizations. Finally, none of the databases mentioned above provide the database compatibility and interoperability that complements their existing applications and staff. The fear of the costs of changing databases, including costs related to application re-coding and personnel re-training, outweigh the expected savings and, therefore, these enterprises remain paralyzed and locked into Oracle. -
SQL & Advanced
SQL & ADVANCED SQL Marcin Blaszczyk (CERN IT-DB) [email protected] AGENDA Goal of this tutorial: Present the overview of basic SQL capabilities Explain several selected advanced SQL features Outline Introduction SQL basics Joins & Complex queries Analytical functions & Set operators Other DB objects (Sequences, Synonyms, DBlinks, Views & Mviews) Indexes & IOTs Partitioning Undo & Flashback technologies Oracle Tutorials 5th of May 2012 SQL LANGUAGE Objective: be able to perform the basic operation of the RDBMS data model create, modify the layout of a table remove a table from the user schema insert data into the table retrieve and manipulate data from one or more tables update/ delete data in a table + . Some more advanced modifications Oracle Tutorials 5th of May 2012 SQL LANGUAGE (2) Structured Query Language Programing language Designed to mange data in relational databases DDL Data Definition Language Creating, replacing, altering, and dropping objects Example: DROP TABLE [TABLE]; DML Data Modification Language Inserting, updating, and deleting rows in a table Example: DELETE FROM [TABLE]; DCL Data Control Language Controlling access to the database and its objects Example: GRANT SELECT ON [TABLE] TO [USER]; Oracle Tutorials 5th of May 2012 SQL LANGUAGE(3) STATEMENT DESCRIPTION SELECT Data Retrieval INSERT UPDATE Data Manipulation Language (DML) DELETE CREATE ALTER DROP Data Definition Language (DDL) RENAME TRUNCATE GRANT Data Control Language (DCL) REVOKE COMMIT Transaction Control ROLLBACK Oracle Tutorials 5th of May 2012 TRANSACTION & UNDO A transaction is a sequence of SQL Statements that Oracle treats as a single unit of work A transaction must be commited or rolled back: COMMIT; - makes permanent the database changes you made during the transaction. -
Alias for Case Statement in Oracle
Alias For Case Statement In Oracle two-facedly.FonsieVitric Connie shrieved Willdon reconnects his Carlenegrooved jimply discloses her and pyrophosphates mutationally, knavishly, butshe reticularly, diocesan flounces hobnail Kermieher apache and never reddest. write disadvantage person-to-person. so Column alias can be used in GROUP a clause alone is different to promote other database management systems such as Oracle and SQL Server See Practice 6-1. Kotlin performs for example, in for alias case statement. If more want just write greater Less evident or butter you fuck do like this equity Case When ColumnsName 0 then 'value1' When ColumnsName0 Or ColumnsName. Normally we mean column names using the create statement and alias them in shape if. The logic to behold the right records is in out CASE statement. As faceted search string manipulation features and case statement in for alias oracle alias? In the following examples and managing the correct behaviour of putting each for case of a prefix oracle autonomous db driver to select command that updates. The four lines with the concatenated case statement then the alias's will work. The following expression jOOQ. Renaming SQL columns based on valve position Modern SQL. SQLite CASE very Simple CASE & Search CASE. Alias on age line ticket do I pretend it once the same path in the. Sql and case in. Gke app to extend sql does that alias for case statement in oracle apex jobs in cases, its various points throughout your. Oracle Creating Joins with the USING Clause w3resource. Multi technology and oracle alias will look further what we get column alias for case statement in oracle. -
Using the Set Operators Questions
UUSSIINNGG TTHHEE SSEETT OOPPEERRAATTOORRSS QQUUEESSTTIIOONNSS http://www.tutorialspoint.com/sql_certificate/using_the_set_operators_questions.htm Copyright © tutorialspoint.com 1.Which SET operator does the following figure indicate? A. UNION B. UNION ALL C. INTERSECT D. MINUS Answer: A. Set operators are used to combine the results of two ormore SELECT statements.Valid set operators in Oracle 11g are UNION, UNION ALL, INTERSECT, and MINUS. When used with two SELECT statements, the UNION set operator returns the results of both queries.However,if there are any duplicates, they are removed, and the duplicated record is listed only once.To include duplicates in the results,use the UNION ALL set operator.INTERSECT lists only records that are returned by both queries; the MINUS set operator removes the second query's results from the output if they are also found in the first query's results. INTERSECT and MINUS set operations produce unduplicated results. 2.Which SET operator does the following figure indicate? A. UNION B. UNION ALL C. INTERSECT D. MINUS Answer: B. UNION ALL Returns the combined rows from two queries without sorting or removing duplicates. sql_certificate 3.Which SET operator does the following figure indicate? A. UNION B. UNION ALL C. INTERSECT D. MINUS Answer: C. INTERSECT Returns only the rows that occur in both queries' result sets, sorting them and removing duplicates. 4.Which SET operator does the following figure indicate? A. UNION B. UNION ALL C. INTERSECT D. MINUS Answer: D. MINUS Returns only the rows in the first result set that do not appear in the second result set, sorting them and removing duplicates. -
SQL Version Analysis
Rory McGann SQL Version Analysis Structured Query Language, or SQL, is a powerful tool for interacting with and utilizing databases through the use of relational algebra and calculus, allowing for efficient and effective manipulation and analysis of data within databases. There have been many revisions of SQL, some minor and others major, since its standardization by ANSI in 1986, and in this paper I will discuss several of the changes that led to improved usefulness of the language. In 1970, Dr. E. F. Codd published a paper in the Association of Computer Machinery titled A Relational Model of Data for Large shared Data Banks, which detailed a model for Relational database Management systems (RDBMS) [1]. In order to make use of this model, a language was needed to manage the data stored in these RDBMSs. In the early 1970’s SQL was developed by Donald Chamberlin and Raymond Boyce at IBM, accomplishing this goal. In 1986 SQL was standardized by the American National Standards Institute as SQL-86 and also by The International Organization for Standardization in 1987. The structure of SQL-86 was largely similar to SQL as we know it today with functionality being implemented though Data Manipulation Language (DML), which defines verbs such as select, insert into, update, and delete that are used to query or change the contents of a database. SQL-86 defined two ways to process a DML, direct processing where actual SQL commands are used, and embedded SQL where SQL statements are embedded within programs written in other languages. SQL-86 supported Cobol, Fortran, Pascal and PL/1. -
“A Relational Model of Data for Large Shared Data Banks”
“A RELATIONAL MODEL OF DATA FOR LARGE SHARED DATA BANKS” Through the internet, I find more information about Edgar F. Codd. He is a mathematician and computer scientist who laid the theoretical foundation for relational databases--the standard method by which information is organized in and retrieved from computers. In 1981, he received the A. M. Turing Award, the highest honor in the computer science field for his fundamental and continuing contributions to the theory and practice of database management systems. This paper is concerned with the application of elementary relation theory to systems which provide shared access to large banks of formatted data. It is divided into two sections. In section 1, a relational model of data is proposed as a basis for protecting users of formatted data systems from the potentially disruptive changes in data representation caused by growth in the data bank and changes in traffic. A normal form for the time-varying collection of relationships is introduced. In Section 2, certain operations on relations are discussed and applied to the problems of redundancy and consistency in the user's model. Relational model provides a means of describing data with its natural structure only--that is, without superimposing any additional structure for machine representation purposes. Accordingly, it provides a basis for a high level data language which will yield maximal independence between programs on the one hand and machine representation and organization of data on the other. A further advantage of the relational view is that it forms a sound basis for treating derivability, redundancy, and consistency of relations. -
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 -
Iseries SQL Programming: You’Ve Got the Power!
iSeries SQL Programming: You’ve Got the Power! By Thibault Dambrine On June 6, 1970, Dr. E. F. Codd, an IBM research employee, published "A Relational Model of Data for Large Shared Data Banks," in the Association of Computer Machinery (ACM) journal, Communications of the ACM. This landmark paper still to this day defines the relational database model. The language, Structured English Query Language (known as SEQUEL) was first developed by IBM Corporation, Inc. using Codd's model. SEQUEL later became SQL. Ironically, IBM was not first to bring the first commercial implementation of SQL to market. In 1979, Relational Software, Inc. was, introducing an SQL product named "Oracle". SQL is the ONLY way to access data on Oracle database systems. The ONLY way to access data on Microsoft SQL Server and I could repeat this sentence with a number of other commercial database products. On the iSeries however, SQL is NOT the only way to access the data. SQL support has only started with V1R1. At that time, AS/400 SQL performance was a problem – a big turnoff for any developer. Because of these facts, many iSeries developers still consider SQL as an optional skill. Many still use SQL only as an advanced data viewer utility, in effect, ranking SQL somewhere north of DSPPFM. Today, one can barely get by anymore as a programmer without knowing SQL. The same is true for all commercial database systems. They all support SQL. The iSeries is no different. It has evolved to compete. As a programming language, SQL is synonymous with - The ability to do more while coding less than a conventional high-level language like C or RPG - Efficiency while processing large amounts of records in a short period of time - A language offering object-oriented like code recycling opportunities, using SQL Functions and SQL Stored Procedures - Easy to learn and easy to use, SQL is a language that allows one to tell the system what results are required without describing how the data will be extracted This article’s first part will describe some common data manipulation methods using SQL. -
Best Practices Managing XML Data
® IBM® DB2® for Linux®, UNIX®, and Windows® Best Practices Managing XML Data Matthias Nicola IBM Silicon Valley Lab Susanne Englert IBM Silicon Valley Lab Last updated: January 2011 Managing XML Data Page 2 Executive summary ............................................................................................. 4 Why XML .............................................................................................................. 5 Pros and cons of XML and relational data ................................................. 5 XML solutions to relational data model problems.................................... 6 Benefits of DB2 pureXML over alternative storage options .................... 8 Best practices for DB2 pureXML: Overview .................................................. 10 Sample scenario: derivative trades in FpML format............................... 11 Sample data and tables................................................................................ 11 Choosing the right storage options for XML data......................................... 16 Selecting table space type and page size for XML data.......................... 16 Different table spaces and page size for XML and relational data ....... 16 Inlining and compression of XML data .................................................... 17 Guidelines for adding XML data to a DB2 database .................................... 20 Inserting XML documents with high performance ................................ 20 Splitting large XML documents into smaller pieces .............................. -
The JOIN Clause
2.1 The JOIN Clause The Join Clause A JOIN clause allows you to access data from two or more tables in a query. A join links to tables on a common key between the two tables. Usually the primary key on one table is compared to the foreign key on another table using the equals ( = ) sign. This is an equijoin or an inner-join. However, other comparison operators are also valid. If column names from each table in the join have the same name, they must be qualified with the table name or a table alias. Below is a basic example of a SQL statement with an inner join clause using explicit syntax. 1 USE world; 2 SELECT city.name AS "City Name", 3 country.name AS "Country Name" 4 FROM country 6 JOIN city 5 ON city.CountryCode = country. Code; Learning MySQL By Example 1 You could write SQL statements more succinctly with an inner join clause using table aliases. Instead of writing out the whole table name to qualify a column, you can use a table alias. 1 USE world; 2 SELECT ci.name AS "City Name", 3 co.name AS "Country Name" 4 FROM city ci 5 JOIN country co 6 ON ci.CountryCode = co.Code; The results of the join query would yield the same results as shown below whether or not table names are completely written out or are represented with table aliases. The table aliases of co for country and ci for city are defined in the FROM clause and referenced in the SELECT and ON clause: Results: Learning MySQL By Example 2 Let us break the statement line by line: USE world; The USE clause sets the database that we will be querying. -
Using Sqlrender
Using SqlRender Martijn J. Schuemie 2021-09-15 Contents 1 Introduction 1 2 SQL parameterization 1 2.1 Substituting parameter values . .1 2.2 Default parameter values . .2 2.3 If-then-else . .2 3 Translation to other SQL dialects 3 3.1 Functions and structures supported by translate . .4 3.2 String concatenation . .5 3.3 Table aliases and the AS keyword . .5 3.4 Temp tables . .5 3.5 Implicit casts . .6 3.6 Case sensitivity in string comparisons . .7 3.7 Schemas and databases . .7 3.8 Optimization for massively parallel processing . .8 4 Debugging parameterized SQL 8 5 Developing R packages that contain parameterized SQL 9 1 Introduction This vignette describes how one could use the SqlRender R package. 2 SQL parameterization One of the main functions of the package is to support parameterization of SQL. Often, small variations of SQL need to be generated based on some parameters. SqlRender offers a simple markup syntax inside the SQL code to allow parameterization. Rendering the SQL based on parameter values is done using the render() function. 2.1 Substituting parameter values The @ character can be used to indicate parameter names that need to be exchange for actual parameter values when rendering. In the following example, a variable called a is mentioned in the SQL. In the call to the render function the value of this parameter is defined: sql <- "SELECT * FROM table WHERE id = @a;" render(sql,a= 123) 1 ## [1] "SELECT * FROM table WHERE id = 123;" Note that, unlike the parameterization offered by most database management systems, it is