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  2. Slowly changing dimension - Wikipedia

    en.wikipedia.org/wiki/Slowly_changing_dimension

    The Start date/time of the second row is equal to the End date/time (or next) of the previous row. The null End_Date in row two indicates the current tuple version. A standardized surrogate high date (e.g. 9999-12-31) may instead be used as an end date so that null-value substitution is not required when querying.

  3. B-tree - Wikipedia

    en.wikipedia.org/wiki/B-tree

    Locate and delete the item, then restructure the tree to retain its invariants, OR; Do a single pass down the tree, but before entering (visiting) a node, restructure the tree so that once the key to be deleted is encountered, it can be deleted without triggering the need for any further restructuring; The algorithm below uses the former strategy.

  4. Vector overlay - Wikipedia

    en.wikipedia.org/wiki/Vector_overlay

    Vector overlay is an operation (or class of operations) in a geographic information system (GIS) for integrating two or more vector spatial data sets. Terms such as polygon overlay, map overlay, and topological overlay are often used synonymously, although they are not identical in the range of operations they include.

  5. Row and column vectors - Wikipedia

    en.wikipedia.org/wiki/Row_and_column_vectors

    The transpose (indicated by T) of any row vector is a column vector, and the transpose of any column vector is a row vector: […] = [] and [] = […]. The set of all row vectors with n entries in a given field (such as the real numbers ) forms an n -dimensional vector space ; similarly, the set of all column vectors with m entries forms an m ...

  6. Data analysis - Wikipedia

    en.wikipedia.org/wiki/Data_analysis

    Once processed and organized, the data may be incomplete, contain duplicates, or contain errors. [21] [22] The need for data cleaning will arise from problems in the way that the datum are entered and stored. [21] Data cleaning is the process of preventing and correcting these errors.

  7. Oxford retains place at top of global university rankings for ...

    www.aol.com/oxford-retains-place-top-global...

    Lighter Side. Medicare. News

  8. Row polymorphism - Wikipedia

    en.wikipedia.org/wiki/Row_polymorphism

    Thanks to row polymorphism, the function may perform two-dimensional transformation on a three-dimensional (in fact, n-dimensional) point, leaving the z coordinate (or any other coordinates) intact. In a more general sense, the function can perform on any record that contains the fields x {\displaystyle x} and y {\displaystyle y} with type ...

  9. Row equivalence - Wikipedia

    en.wikipedia.org/wiki/Row_equivalence

    Elementary row operations do not affect the row space of a matrix. In particular, any two row equivalent matrices have the same row space. Any matrix can be reduced by elementary row operations to a matrix in reduced row echelon form. Two matrices in reduced row echelon form have the same row space if and only if they are equal.