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Hypersonic SQL
HSQLDB (''Hyper SQL Database'') is a relational database management system written in Java. It has a JDBC driver and supports a large subset of SQL-92, SQL:2008, SQL:2011, and SQL:2016 standards. It offers a fast, small (around 1300 kilobytes in version 2.2) database engine which offers both in-memory and disk-based tables. Both embedded and server modes are available. Additionally, it includes tools such as a minimal Web server, command line and GUI management tools (can be run as applets), and a number of demonstration examples. It can run on Java runtimes from version 1.1 upwards, including free Java implementations such as Kaffe. HSQLDB is available under a BSD license. It is used as a database and persistence engine in many open source software projects, such as descendants of OpenOffice.org Base (i.e., Apache OpenOffice Base, LibreOffice Base, etc.), and the Jitsi VoIP and video-conference client since version 2.6. It is also used in commercial products, such as Mathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross-platform
In computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several computing platforms. Some cross-platform software requires a separate build for each platform, but some can be directly run on any platform without special preparation, being written in an interpreted language or compiled to portable bytecode for which the interpreters or run-time packages are common or standard components of all supported platforms. For example, a cross-platform application may run on Microsoft Windows, Linux, and macOS. Cross-platform software may run on many platforms, or as few as two. Some frameworks for cross-platform development are Codename One, Kivy, Qt, Flutter, NativeScript, Xamarin, Phonegap, Ionic, and React Native. Platforms ''Platform'' can refer to the type of processor (CPU) or other hardware on which an operating system (OS) or application runs, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apache OpenOffice Base
The Apache () are a group of culturally related Native American tribes in the Southwestern United States, which include the Chiricahua, Jicarilla, Lipan, Mescalero, Mimbreño, Ndendahe (Bedonkohe or Mogollon and Nednhi or Carrizaleño and Janero), Salinero, Plains (Kataka or Semat or " Kiowa-Apache") and Western Apache ( Aravaipa, Pinaleño, Coyotero, Tonto). Distant cousins of the Apache are the Navajo, with whom they share the Southern Athabaskan languages. There are Apache communities in Oklahoma and Texas, and reservations in Arizona and New Mexico. Apache people have moved throughout the United States and elsewhere, including urban centers. The Apache Nations are politically autonomous, speak several different languages, and have distinct cultures. Historically, the Apache homelands have consisted of high mountains, sheltered and watered valleys, deep canyons, deserts, and the southern Great Plains, including areas in what is now Eastern Arizona, Northern Mexico ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apache Derby
Apache Derby (previously distributed as IBM Cloudscape) is a relational database management system (RDBMS) developed by the Apache Software Foundation that can be embedded in Java programs and used for online transaction processing. It has a 3.5 MB disk-space footprint. Apache Derby is developed as an open source project under the Apache 2.0 license. For a time, Oracle distributed the same binaries under the name Java DB. In June 2015 they announced that for JDK 9 they would no longer be doing so. History Apache Derby originated at Cloudscape Inc, an Oakland, California, start-up founded in 1996 by Nat Wyatt and Howard Torf to develop Java database technology. The first release of the database engine, then called JBMS, was in 1997. Subsequently, the product was renamed Cloudscape and releases were made about every six months. In 1999 Informix Software, Inc., acquired Cloudscape, Inc. In 2001 IBM acquired the database assets of Informix Software, including Cloudscape. The data ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Relational Database Management Systems
The following tables compare general and technical information for a number of relational database management systems. Please see the individual products' articles for further information. Unless otherwise specified in footnotes, comparisons are based on the stable versions without any add-ons, extensions or external programs. General information Operating system support The operating systems that the RDBMSes can run on. Fundamental features Information about what fundamental RDBMS features are implemented natively. Note (1): Currently only supports read uncommited transaction isolation. Version 1.9 adds serializable isolation and version 2.0 will be fully ACID compliant. Note (2): MariaDB and MySQL provide ACID compliance through the default InnoDB storage engine. Note (3): "For other than InnoDB storage engines, MySQL Server parses and ignores the FOREIGN KEY and REFERENCES syntax in CREATE TABLE statements. The CHECK clause is parsed but ignored by all storage engine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Relational Database Management Systems
This is a list of relational database management systems. List of software * 4th Dimension *Access Database Engine (formerly known as Jet Database Engine) *Adabas D *Airtable *Apache Derby *Apache Ignite * Aster Data *Amazon Aurora *Altibase * CA Datacom * CA IDMS *Clarion *ClickHouse *Clustrix *CockroachDB *CSQL *CUBRID * DataEase *DataFlex *Database Management Library *Dataphor * dBase *Derby (aka Java DB) *Empress Embedded Database * Exasol *Extensible Storage Engine *EnterpriseDB *eXtremeDB * FileMaker Pro *Firebird *FoundationDB * FrontBase *Greenplum * GroveSite * H2 *Helix *HSQLDB *IBM Db2 * IBM Lotus Approach *Infobright *Informix * Ingres *InterBase *InterSystems Caché * InterSystems IRIS Data Platform * Linter *MariaDB *MaxDB *Microsoft SQL Server * Microsoft SQL Server Express * SQL Azure (Cloud SQL Server) *Microsoft Visual FoxPro *Mimer SQL *MonetDB * mSQL *MySQL *Netezza *NexusDB *NonStop SQL *NuoDB *Omnis Studio * OpenLink Virtuoso (Open Source Edition) * OpenLink V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-phase Locking
In databases and transaction processing, two-phase locking (2PL) is a concurrency control method that guarantees serializability.Phil Bernstein, Philip A. Bernstein, Vassos Hadzilacos, Nathan Goodman (1987) ''Concurrency Control and Recovery in Database Systems'' Addison Wesley Publishing Company, Gerhard Weikum, Gottfried Vossen (2001) ''Transactional Information Systems'' Elsevier, It is also the name of the resulting set of database transaction schedule (computer science), schedules (histories). The protocol uses lock (computer science), locks, applied by a transaction to data, which may block (interpreted as signals to stop) other transactions from accessing the same data during the transaction's life. By the 2PL protocol, locks are applied and removed in two phases: # Expanding phase: locks are acquired and no locks are released. # Shrinking phase: locks are released and no locks are acquired. Two types of locks are used by the basic protocol: ''Shared'' and ''Exclusive'' lock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Database Connectivity
Java Database Connectivity (JDBC) is an application programming interface (API) for the programming language Java, which defines how a client may access a database. It is a Java-based data access technology used for Java database connectivity. It is part of the Java Standard Edition platform, from Oracle Corporation. It provides methods to query and update data in a database, and is oriented toward relational databases. A JDBC-to-ODBC bridge enables connections to any ODBC-accessible data source in the Java virtual machine (JVM) host environment. History and implementation Sun Microsystems released JDBC as part of Java Development Kit (JDK) 1.1 on February 19, 1997. Since then it has been part of the Java Platform, Standard Edition (Java SE). The JDBC classes are contained in the Java package and . Starting with version 3.1, JDBC has been developed under the Java Community Process. JSR 54 specifies JDBC 3.0 (included in J2SE 1.4), JSR 114 specifies the JDBC Rowset additions, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregate Function
In database management, an aggregate function or aggregation function is a function where the values of multiple rows are grouped together to form a single summary value. Common aggregate functions include: * Average (i.e., arithmetic mean) * Count * Maximum * Median * Minimum * Mode * Range * Sum Others include: * Nanmean (mean ignoring NaN values, also known as "nil" or "null") * Stddev Formally, an aggregate function takes as input a set, a multiset (bag), or a list from some input domain and outputs an element of an output domain . The input and output domains may be the same, such as for SUM, or may be different, such as for COUNT. Aggregate functions occur commonly in numerous programming languages, in spreadsheets, and in relational algebra. The listagg function, as defined in the SQL:2016 standard aggregates data from multiple rows into a single concatenated string. Decomposable aggregate functions Aggregate functions present a bottleneck, because they poten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Set Operations (SQL)
Set operations allow the results of multiple queries to be combined into a single result set. Set operators include UNION, INTERSECT, and EXCEPT. UNION operator In SQL the UNION clause combines the results of two SQL queries into a single table of all matching rows. The two queries must result in the same number of columns and compatible data types in order to unite. Any duplicate records are automatically removed unless UNION ALL is used. UNION can be useful in data warehouse applications where tables are not perfectly normalized. A simple example would be a database having tables sales2005 and sales2006 that have identical structures but are separated because of performance considerations. A UNION query could combine results from both tables. Note that UNION ALL does not guarantee the order of rows. Rows from the second operand may appear before, after, or mixed with rows from the first operand. In situations where a specific order is desired, ORDER BY must be used. Note ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comma-separated Values
A comma-separated values (CSV) file is a delimited text file that uses a comma to separate values. Each line of the file is a data record. Each record consists of one or more fields, separated by commas. The use of the comma as a field separator is the source of the name for this file format. A CSV file typically stores tabular data (numbers and text) in plain text, in which case each line will have the same number of fields. The CSV file format is not fully standardized. Separating fields with commas is the foundation, but commas in the data or embedded line breaks have to be handled specially. Some implementations disallow such content while others surround the field with quotation marks, which yet again creates the need for escaping if quotation marks are present in the data. The term "CSV" also denotes several closely-related delimiter-separated formats that use other field delimiters such as semicolons. These include tab-separated values and space-separated values. A d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isolation (database Systems)
In database systems, isolation determines how transaction integrity is visible to other users and systems. A lower isolation level increases the ability of many users to access the same data at the same time, but increases the number of concurrency effects (such as dirty reads or lost updates) users might encounter. Conversely, a higher isolation level reduces the types of concurrency effects that users may encounter, but requires more system resources and increases the chances that one transaction will block another. Isolation is typically defined at database level as a property that defines how or when the changes made by one operation become visible to others. On older systems, it may be implemented systemically, for example through the use of temporary tables. In two-tier systems, a transaction processing (TP) manager is required to maintain isolation. In n-tier systems (such as multiple websites attempting to book the last seat on a flight), a combination of stored procedu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiversion Concurrency Control
Multiversion concurrency control (MCC or MVCC), is a concurrency control method commonly used by database management systems to provide concurrent access to the database and in programming languages to implement transactional memory. Description Without concurrency control, if someone is reading from a database at the same time as someone else is writing to it, it is possible that the reader will see a half-written or inconsistent piece of data. For instance, when making a wire transfer between two bank accounts if a reader reads the balance at the bank when the money has been withdrawn from the original account and before it was deposited in the destination account, it would seem that money has disappeared from the bank. Isolation is the property that provides guarantees in the concurrent accesses to data. Isolation is implemented by means of a concurrency control protocol. The simplest way is to make all readers wait until the writer is done, which is known as a read-write lock. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
