Extendible hashing

extensible hashing
Extendible hashing is a type of hash system which treats a hash as a bit string, and uses a trie for bucket lookup. Because of the hierarchical nature of the system, re-hashing is an incremental operation (done one bucket at a time, as needed). This means that time-sensitive applications are less affected by table growth than by standard full-table rehashes.

Partition (database)

partitioninghorizontal partitioningpartitions
A partition is a division of a logical database or its constituent elements into distinct independent parts. Database partitioning is normally done for manageability, performance or availability reasons, or for load balancing.


GeoJSON is an open standard format designed for representing simple geographical features, along with their non-spatial attributes. It is based on JSON, the JavaScript Object Notation.


Scalability is the capability of a system, network, or process to handle a growing amount of work, or its potential to be enlarged to accommodate that growth. For example, a system is considered scalable if it is capable of increasing its total output under an increased load when resources (typically hardware) are added. An analogous meaning is implied when the word is used in an economic context, where a company's scalability implies that the underlying business model offers the potential for economic growth within the company.

Log-structured merge-tree

In computer science, the log-structured merge-tree (or LSM tree) is a data structure with performance characteristics that make it attractive for providing indexed access to files with high insert volume, such as transactional log data. LSM trees, like other search trees, maintain key-value pairs. LSM trees maintain data in two or more separate structures, each of which is optimized for its respective underlying storage medium; data is synchronized between the two structures efficiently, in batches.


Zynga Game NetworkZynga Game Network Inc.Zynga Inc
Zynga Inc. is an American social game developer running social video game services founded in April 2007 and headquartered in San Francisco, California, United States. The company primarily focuses on mobile gaming, offering the games on mobile devices, including smartphones and tablets on Apple's iOS and Google's Android operating systems, and on social networking platforms such as Facebook. Zynga states its mission as "connecting the world through games."

Fractal tree index

Fractal Tree indexing
In computer science, a fractal tree index is a tree data structure that keeps data sorted and allows searches and sequential access in the same time as a B-tree but with insertions and deletions that are asymptotically faster than a B-tree. Like a B-tree, a fractal tree index is a generalization of a binary search tree in that a node can have more than two children. Furthermore, unlike a B-tree, a fractal tree index has buffers at each node, which allow insertions, deletions and other changes to be stored in intermediate locations.

Naver (corporation)

NaverNHNNaver Corporation
Naver Corporation (KRX: 035420) is an Internet content service company headquartered in Seongnam, South Korea that operates the Korean search engine Naver. Naver established itself as an early pioneer in the use of user-generated content through the creation of the online Q&A platform Knowledge iN. Naver also manages global mobile services such as the mobile messenger LINE, video messenger Snow, and group communication service BAND.

Surrogate key

A surrogate key (or synthetic key, entity identifier, system-generated key, database sequence number, factless key, technical key, or arbitrary unique identifier) in a database is a unique identifier for either an entity in the modeled world or an object in the database. The surrogate key is not derived from application data, unlike a natural (or business) key which is derived from application data.


MongoDB is a cross-platform document-oriented database program. It is issued under the Server Side Public License (SSPL) version 1, which was submitted for certification to the Open Source Initiative but later withdrawn in lieu of SSPL version 2 . Classified as a NoSQL database program, MongoDB uses JSON-like documents with schemata. MongoDB is developed by MongoDB Inc.

Dynamic array

dynamic arraysarraysarray
In computer science, a dynamic array, growable array, resizable array, dynamic table, mutable array, or array list is a random access, variable-size list data structure that allows elements to be added or removed. It is supplied with standard libraries in many modern mainstream programming languages. Dynamic arrays overcome a limit of static arrays, which have a fixed capacity that needs to be specified at allocation.

Big O notation

Obig-O notationΘ
Big O notation is a mathematical notation that describes the limiting behavior of a function when the argument tends towards a particular value or infinity. It is a member of a family of notations invented by Paul Bachmann, Edmund Landau, and others, collectively called Bachmann–Landau notation or asymptotic notation.


ebookersOrbitz Worldwideaway.com
Orbitz.com is a travel fare aggregator website and travel metasearch engine. The website is owned by Orbitz Worldwide, Inc., a subsidiary of Expedia Group. It is headquartered in the Citigroup Center, Chicago, Illinois.

DB-Engines ranking

The DB-Engines Ranking ranks database management systems by popularity, covering over 340 systems. The ranking criteria include number of search engine results when searching for the system names, Google Trends, Stack Overflow discussions, job offers with mentions of the systems, number of profiles in professional networks such as LinkedIn, mentions in social networks such as Twitter. The ranking is updated monthly. It has been described and cited in various database-related articles.


GitHub Inc. is a web-based hosting service for version control using Git. It is mostly used for computer code. It offers all of the distributed version control and source code management (SCM) functionality of Git as well as adding its own features.


map reducemap-reducemap/reduce
MapReduce is a programming model and an associated implementation for processing and generating big data sets with a parallel, distributed algorithm on a cluster.

Apache Cassandra

Apache Cassandra is a free and open-source, distributed, wide column store, NoSQL database management system designed to handle large amounts of data across many commodity servers, providing high availability with no single point of failure. Cassandra offers robust support for clusters spanning multiple datacenters, with asynchronous masterless replication allowing low latency operations for all clients.

Google Groups

GroupsDejanewsGoogle Group
Google Groups is a service from Google that provides discussion groups for people sharing common interests. The Groups service also provides a gateway to Usenet newsgroups via a shared user interface.

Replication (computing)

replicationdata replicationreplicated
Replication in computing involves sharing information so as to ensure consistency between redundant resources, such as software or hardware components, to improve reliability, fault-tolerance, or accessibility.

Stack Overflow

Stack Overflow is a question and answer site for professional and enthusiast programmers. It is a privately held website, the flagship site of the Stack Exchange Network, created in 2008 by Jeff Atwood and Joel Spolsky. It features questions and answers on a wide range of topics in computer programming. It was created to be a more open alternative to earlier question and answer sites such as Experts-Exchange. The name for the website was chosen by voting in April 2008 by readers of Coding Horror, Atwood's popular programming blog.

Data center

data centersdata centredatacenter
A data center (American English) or data centre (British English) is a building, dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommunications and storage systems.


Udemy.com is an online learning platform. It is aimed at professional adults. Unlike academic massive open online course (MOOC) programs which are driven by traditional collegiate coursework, Udemy uses content from online content creators to sell for profit. Udemy provides tools which enable users to create a course, promote it and earn money from student tuition charges.

Mesosphere, Inc.

Mesosphere is an American technology company based in San Francisco, California which develops software for data centers based on Apache Mesos. It calls its product Datacenter Operating System.

CAP theorem

AP systemavailability under partitionCAP
In theoretical computer science, the CAP theorem, also named Brewer's theorem after computer scientist Eric Brewer, states that it is impossible for a distributed data store to simultaneously provide more than two out of the following three guarantees:

Network partition

partition tolerancenetwork partitioningNetwork Partition for Optimization
A network partition refers to network decomposition into relatively independent subnets for their separate optimization as well as network split due to the failure of network devices. In both cases the partition-tolerant behavior of subnets is expected. This means that even after the network is partitioned into multiple sub-systems, it still works correctly.