enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Rolling hash - Wikipedia

    en.wikipedia.org/wiki/Rolling_hash

    A rolling hash (also known as recursive hashing or rolling checksum) is a hash function where the input is hashed in a window that moves through the input.. A few hash functions allow a rolling hash to be computed very quickly—the new hash value is rapidly calculated given only the old hash value, the old value removed from the window, and the new value added to the window—similar to the ...

  3. Window function (SQL) - Wikipedia

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

    In SQL, a window function or analytic function [1] is a function which uses values from one or multiple rows to return a value for each row. (This contrasts with an aggregate function, which returns a single value for multiple rows.) Window functions have an OVER clause; any function without an OVER clause is not a window function, but rather ...

  4. Rollback (data management) - Wikipedia

    en.wikipedia.org/wiki/Rollback_(data_management)

    SQL refers to Structured Query Language, a kind of language used to access, update and manipulate database. In SQL, ROLLBACK is a command that causes all data changes since the last START TRANSACTION or BEGIN to be discarded by the relational database management systems (RDBMS), so that the state of the data is "rolled back" to the way it was before those changes were made.

  5. Rolling-element bearing - Wikipedia

    en.wikipedia.org/wiki/Rolling-element_bearing

    The relative motion of the races causes the rolling elements to roll with very little rolling resistance and with little sliding. One of the earliest and best-known rolling-element bearings are sets of logs laid on the ground with a large stone block on top. As the stone is pulled, the logs roll along the ground with little sliding friction. As ...

  6. Rolling (metalworking) - Wikipedia

    en.wikipedia.org/wiki/Rolling_(metalworking)

    In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness, to make the thickness uniform, and/or to impart a desired mechanical property. The concept is similar to the rolling of dough. Rolling is classified according to the temperature of the metal rolled.

  7. Plate rolling machine - Wikipedia

    en.wikipedia.org/wiki/Plate_rolling_machine

    When rolling, the top roll presses the metal plate between the two side rolls. The advantage of having the variable three roll is the ability to roll many thicknesses and diameters of cylinders. For example; The side-rolls are what produce the mechanical advantage. With the side rolls all the way open, one has the maximum mechanical advantage ...

  8. Rolling circle replication - Wikipedia

    en.wikipedia.org/wiki/Rolling_circle_replication

    Rolling circle replication produces multiple copies of a single circular template. Rolling circle replication ( RCR ) is a process of unidirectional nucleic acid replication that can rapidly synthesize multiple copies of circular molecules of DNA or RNA , such as plasmids , the genomes of bacteriophages , and the circular RNA genome of viroids .

  9. Bascule bridge - Wikipedia

    en.wikipedia.org/wiki/Bascule_bridge

    The "Scherzer" rolling lift is a refinement patented in 1893 by American engineer William Donald Scherzer. [3] The rarer Rall type combines rolling lift with longitudinal motion on trunnions when opening. [4] It was patented (1901) by Theodor Rall. [2] [4] [5] One of the few surviving examples is the Broadway Bridge (1913), in Portland, Oregon ...