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  2. Database schema - Wikipedia

    en.wikipedia.org/wiki/Database_schema

    Visual representation often may also be exported as a production-ready source code made in DB-compatible languages like SQL. The database schema is the structure of a database described in a formal language supported typically by a relational database management system (RDBMS).

  3. Character displacement - Wikipedia

    en.wikipedia.org/wiki/Character_displacement

    Character displacement was first explicitly explained by William L. Brown Jr. and E. O. Wilson in 1956: "Two closely related species have overlapping ranges. [1] In the parts of the ranges where one species occurs alone, the populations of that species are similar to the other species and may even be very difficult to distinguish from it.

  4. Interval tree - Wikipedia

    en.wikipedia.org/wiki/Interval_tree

    For example, when testing if the given interval [40 ,60) overlaps the intervals in the tree shown above, we see that it does not overlap the interval [20, 36) in the root, but since the root's low value (20) is less than the sought high value (60), we must search the right subtree. The left subtree's maximum high of 41 exceeds the sought low ...

  5. Spatial database - Wikipedia

    en.wikipedia.org/wiki/Spatial_database

    A spatial index is used by a spatial database to optimize spatial queries.Database systems use indices to quickly look up values by sorting data values in a linear (e.g. alphabetical) order; however, this way of indexing data is not optimal for spatial queries in two- or three-dimensional space.

  6. Data-flow diagram - Wikipedia

    en.wikipedia.org/wiki/Data-flow_diagram

    The name of the warehouse is a plural noun (e.g. orders)—it derives from the input and output streams of the warehouse. The warehouse does not have to be just a data file but can also be, for example, a folder with documents, a filing cabinet, or a set of optical discs. Therefore, viewing the warehouse in a DFD is independent of implementation.

  7. Glossary of botanical terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_botanical_terms

    Having geographically separate, non-overlapping ranges of distribution. [17] Contrast sympatric. alternate 1. (adj.) (of leaves or flower s) Borne singly at different levels along a stem, including spiralled parts. Contrast opposite. 2. (prep.) Occurring between something else, e.g. stamen s alternating with petal s. alternipetalous

  8. Disjunct distribution - Wikipedia

    en.wikipedia.org/wiki/Disjunct_distribution

    Range of the snail Elona quimperiana, an example of a disjunct distribution. In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but considerably separated from each other geographically. The causes are varied and might demonstrate either the expansion or contraction of a species' range. [1]

  9. Dice-Sørensen coefficient - Wikipedia

    en.wikipedia.org/wiki/Dice-Sørensen_coefficient

    For example, to calculate the similarity between: night nacht. We would find the set of bigrams in each word: {ni,ig,gh,ht} {na,ac,ch,ht} Each set has four elements, and the intersection of these two sets has only one element: ht. Inserting these numbers into the formula, we calculate, s = (2 · 1) / (4 + 4) = 0.25.