When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Table (database) - Wikipedia

    en.wikipedia.org/wiki/Table_(database)

    In a database, a table is a collection of related data organized in table format; consisting of columns and rows.. In relational databases, and flat file databases, a table is a set of data elements (values) using a model of vertical columns (identifiable by name) and horizontal rows, the cell being the unit where a row and column intersect. [1]

  3. Database index - Wikipedia

    en.wikipedia.org/wiki/Database_index

    To process this statement without an index the database software must look at the last_name column on every row in the table (this is known as a full table scan). With an index the database simply follows the index data structure (typically a B-tree ) until the Smith entry has been found; this is much less computationally expensive than a full ...

  4. Comma-separated values - Wikipedia

    en.wikipedia.org/wiki/Comma-separated_values

    Comma-separated values (CSV) is a text file format that uses commas to separate values, and newlines to separate records. A CSV file stores tabular data (numbers and text) in plain text, where each line of the file typically represents one data record. Each record consists of the same number of fields, and these are separated by commas in the ...

  5. Array slicing - Wikipedia

    en.wikipedia.org/wiki/Array_slicing

    Thus, if we have a vector containing elements (2, 5, 7, 3, 8, 6, 4, 1), and we want to create an array slice from the 3rd to the 6th items, we get (7, 3, 8, 6). In programming languages that use a 0-based indexing scheme, the slice would be from index 2 to 5. Reducing the range of any index to a single value effectively eliminates that index.

  6. Select (SQL) - Wikipedia

    en.wikipedia.org/wiki/Select_(SQL)

    This is also known as a Vertical Partition in some database terms, restricting query output to view only specified fields or columns. With the same table, the query SELECT * FROM T WHERE C1 = 1 will result in all the elements of all the rows where the value of column C1 is '1' being shown – in relational algebra terms, a selection will be ...

  7. Relation (database) - Wikipedia

    en.wikipedia.org/wiki/Relation_(database)

    An attribute value is an attribute name paired with an element of that attribute's domain, and a tuple is a set of attribute values in which no two distinct elements have the same name. Thus, in some accounts, a tuple is described as a function , mapping names to values.

  8. For loop - Wikipedia

    en.wikipedia.org/wiki/For_loop

    For instance, within the loop a reference to element I of an array would likely employ the auxiliary variable (especially if it were held in a machine register), but if I is a parameter to some routine (for instance, a print-statement to reveal its value), it would likely be a reference to the proper variable I instead. It is best to avoid such ...

  9. Delta encoding - Wikipedia

    en.wikipedia.org/wiki/Delta_encoding

    A delta can be defined in 2 ways, symmetric delta and directed delta.A symmetric delta can be expressed as (,) = (),where and represent two versions.. A directed delta, also called a change, is a sequence of (elementary) change operations which, when applied to one version , yields another version (note the correspondence to transaction logs in databases).