PostgreSQLPostgreSQL (ˈpoʊstɡɹɛs_ˌkjuː_ˈɛl, ), also known as Postgres, is a free and open-source relational database management system (RDBMS) emphasizing extensibility and SQL compliance. It was originally named POSTGRES, referring to its origins as a successor to the Ingres database developed at the University of California, Berkeley. In 1996, the project was renamed to PostgreSQL to reflect its support for SQL. After a review in 2007, the development team decided to keep the name PostgreSQL and the alias Postgres.
Query planA query plan (or query execution plan) is a sequence of steps used to access data in a SQL relational database management system. This is a specific case of the relational model concept of access plans. Since SQL is declarative, there are typically many alternative ways to execute a given query, with widely varying performance. When a query is submitted to the database, the query optimizer evaluates some of the different, correct possible plans for executing the query and returns what it considers the best option.
DatalogDatalog is a declarative logic programming language. While it is syntactically a subset of Prolog, Datalog generally uses a bottom-up rather than top-down evaluation model. This difference yields significantly different behavior and properties from Prolog. It is often used as a query language for deductive databases. Datalog has been applied to problems in data integration, networking, program analysis, and more. A Datalog program consists of facts, which are statements that are held to be true, and rules, which say how to deduce new facts from known facts.
Bitmap indexA bitmap index is a special kind of database index that uses bitmaps. Bitmap indexes have traditionally been considered to work well for low-cardinality columns, which have a modest number of distinct values, either absolutely, or relative to the number of records that contain the data. The extreme case of low cardinality is Boolean data (e.g., does a resident in a city have internet access?), which has two values, True and False. Bitmap indexes use bit arrays (commonly called bitmaps) and answer queries by performing bitwise logical operations on these bitmaps.
Drizzle (database server)Drizzle is a discontinued free software/open-source relational database management system (DBMS) that was forked from the now-defunct 6.0 development branch of the MySQL DBMS. Like MySQL, Drizzle had a client/server architecture and uses SQL as its primary command language. Old Drizzle files are distributed under version 2 and 3 of the GNU General Public License (GPL) with portions, including the protocol drivers and replication messaging under the BSD license. Early work on the fork was done mid-2008 by Brian Aker.
TarantoolTarantool is an in-memory computing platform with a flexible data schema, best used for creating high-performance applications. Two main parts of it are an in-memory database and a Lua application server. Tarantool maintains data in memory and ensures crash resistance with write-ahead logging and snapshotting. It includes a Lua interpreter and interactive console, but also accepts connections from programs in several other languages. Mail.
Microsoft AccessMicrosoft Access is a database management system (DBMS) from Microsoft that combines the relational Access Database Engine (ACE) with a graphical user interface and software-development tools. It is a member of the Microsoft 365 suite of applications, included in the Professional and higher editions or sold separately. Microsoft Access stores data in its own format based on the Access Database Engine (formerly Jet Database Engine). It can also import or link directly to data stored in other applications and databases.
In-memory processingIn computer science, in-memory processing (PIM) is a computer architecture for processing data stored in an in-memory database. In-memory processing improves the power usage and performance of moving data between the processor and the main memory. Older systems have been based on disk storage and relational databases using Structured Query Language, which are increasingly regarded as inadequate to meet business intelligence (BI) needs.
Dimensional modelingDimensional modeling (DM) is part of the Business Dimensional Lifecycle methodology developed by Ralph Kimball which includes a set of methods, techniques and concepts for use in data warehouse design. The approach focuses on identifying the key business processes within a business and modelling and implementing these first before adding additional business processes, as a bottom-up approach. An alternative approach from Inmon advocates a top down design of the model of all the enterprise data using tools such as entity-relationship modeling (ER).
