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  2. Tuple-versioning - Wikipedia

    en.wikipedia.org/wiki/Tuple-versioning

    Tuple-versioning (also called point-in-time) is a mechanism used in a relational database management system to store past states of a relation. Normally, only the current state is captured. Using tuple-versioning techniques, typically two values for time are stored along with each tuple: a start time and an end time. These two values indicate ...

  3. Tuple relational calculus - Wikipedia

    en.wikipedia.org/wiki/Tuple_relational_calculus

    (t.name = "Codd") — tuple t has a name attribute and its value is "Codd" Book(t) — tuple t is present in relation Book. The formal semantics of such atoms is defined given a database db over S and a tuple variable binding val : V → T D that maps tuple variables to tuples over the domain in S: v.a = w.b is true if and only if val(v)(a ...

  4. Relation (database) - Wikipedia

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

    Relation, tuple, and attribute represented as table, row, and column respectively In database theory, a relation , as originally defined by E. F. Codd , [ 1 ] is a set of tuples (d 1 ,d 2 ,...,d n ), where each element d j is a member of D j , a data domain .

  5. Spreadsheet - Wikipedia

    en.wikipedia.org/wiki/Spreadsheet

    Example of a spreadsheet holding data about a group of audio tracks. A spreadsheet is a computer application for computation, organization, analysis and storage of data in tabular form. [1] [2] [3] Spreadsheets were developed as computerized analogs of paper accounting worksheets. [4] The program operates on data entered in cells of a table.

  6. Tuple - Wikipedia

    en.wikipedia.org/wiki/Tuple

    A 1‑tuple is called a single (or singleton), a 2‑tuple is called an ordered pair or couple, and a 3‑tuple is called a triple (or triplet). The number n can be any nonnegative integer . For example, a complex number can be represented as a 2‑tuple of reals, a quaternion can be represented as a 4‑tuple, an octonion can be represented as ...

  7. Microsoft Excel - Wikipedia

    en.wikipedia.org/wiki/Microsoft_Excel

    A chart created with data from a Microsoft Excel spreadsheet that only saves the chart. To save the chart and spreadsheet save as .XLS. XLC is not supported in Excel 2007 or in any newer versions of Excel. Dialog .xld: Used in older versions of Excel. Archive .xlk: A backup of an Excel Spreadsheet Add-in (DLL) .xll

  8. Lotus 1-2-3 - Wikipedia

    en.wikipedia.org/wiki/Lotus_1-2-3

    Lotus 1-2-3 is a discontinued spreadsheet program from Lotus Software (later part of IBM).It was the first killer application of the IBM PC, was hugely popular in the 1980s, and significantly contributed to the success of IBM PC-compatibles in the business market.

  9. System time - Wikipedia

    en.wikipedia.org/wiki/System_time

    The Boost Date/Time Library (C++) The Boost Chrono Library (C++) The Chronos Date/Time Library (Smalltalk) Joda Time, The Joda Date/Time Library (Java) The Perl DateTime Project Archived 2009-02-19 at the Wayback Machine (Perl) date: Ruby Standard Library Documentation (Ruby)