Index

An index is an indirect shortcut derived from and pointing into a greater volume of values, data, information or knowledge. Index may refer to:

Business

Publishing

Database index

A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time a database table is accessed. Indexes can be created using one or more columns of a database table, providing the basis for both rapid random lookups and efficient access of ordered records.

An index is a copy of select columns of data from a table that can be searched very efficiently that also includes a low-level disk block address or direct link to the complete row of data it was copied from. Some databases extend the power of indexing by letting developers create indices on functions or expressions. For example, an index could be created on upper(last_name), which would only store the upper case versions of the last_name field in the index. Another option sometimes supported is the use of partial indices, where index entries are created only for those records that satisfy some conditional expression. A further aspect of flexibility is to permit indexing on user-defined functions, as well as expressions formed from an assortment of built-in functions.

Index (statistics)

In statistics and research design, an index is a composite statistic – a measure of changes in a representative group of individual data points, or in other words, a compound measure that aggregates multiple indicators. Indexes summarize and rank specific observations.

Much data in the field of social sciences is represented in various indices such as Gender Gap Index, Human Development Index or the Dow Jones Industrial Average.

Item in indexes are usually weighted equally, unless there are some reasons against it (for example, if two items reflect essentially the same aspect of a variable, they could have a weight of 0.5 each).

Constructing the items involves four steps. First, items should be selected based on their face validity, unidimensionality, the degree of specificity in which a dimension is to be measured, and their amount of variance. Items should be empirically related to one another, which leads to the second step of examining their multivariate relationships. Third, indexes scores are designed, which involves determining their score ranges and weights for the items. Finally, indexes should be validateds, which involves testing whether they can predict indicators related to the measured variable not used in their construction.

Jazz

Jazz is a music genre that originated from African American communities of New Orleans in the United States during the late 19th and early 20th centuries. It emerged in the form of independent traditional and popular musical styles, all linked by the common bonds of African American and European American musical parentage with a performance orientation. Jazz spans a period of over a hundred years, encompassing a very wide range of music, making it difficult to define. Jazz makes heavy use of improvisation, polyrhythms, syncopation and the swing note, as well as aspects of European harmony, American popular music, the brass band tradition, and African musical elements such as blue notes and African-American styles such as ragtime. Although the foundation of jazz is deeply rooted within the black experience of the United States, different cultures have contributed their own experience to the music as well. Intellectuals around the world have hailed jazz as "one of America's original art forms".

Jazz (Wallace Roney album)

Jazz is an album by jazz artist Wallace Roney released in 2007.

Track listing

Personnel

Jazz (Kanso series)

Jazz (Kanso series) is a series of 20 paintings made by Nabil Kanso in 1978-79. The subjects of the works are based on the jazz music and the entertainments night life in New York and New Orleans. The paintings are done in oil and acrylic on canvas measuring 224 X 182 cm (88 X 72 inches) each. Their compositions reflect predominant red tonality built with broad brushstrokes. Works from the series were exhibited in Atlanta in 1985.

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