If not specified, the default is 1.
If a default value is not specified, NULL is returned. If not specified, the function treats all rows of the query result set as a single group. For more information, see Deterministic and Nondeterministic Functions. The following example uses the LAG function to return the difference in sales quotas for a specific employee over previous years.
Notice that because there is no lag value available for the first row, the default of zero 0 is returned.
The following example uses the LAG function to compare year-to-date sales between employees. The LAG function is applied to each partition separately and computation restarts for each partition. Notice that because there is no lag value available for the first row of each partition, the default of zero 0 is returned.
The following example demonstrates specifying a variety of arbitrary expressions in the LAG function syntax. Lag is especially noticeable when playing online games via dial-up connections. Lag primarily occurs because data requires a certain amount of travel time between applications, compounded by data application processing time.
Specific types of lag include: Home Dictionary Tags Data Management. Definition - What does Lag mean? Techopedia explains Lag Lag primarily occurs because data requires a certain amount of travel time between applications, compounded by data application processing time.
Local video gaming lag: Most video games suffer a degree of lag. Video gaming lag is measured according to noticeable delay.
Lag inconvenience and frustration level largely depend on the type of game played. In shooting games, lag can quickly become a serious issue, but in turn-based strategy games, lag is well tolerated. Online multiplayer gaming lag: Again, the type of game played dictates the user's level of lag frustration.
In online cloud gaming, a complete game is hosted on a central server that allows a user to operate a local thin client for forwarding streaming game controller actions. The game server streams the video game frame by frame to the thin client in a low-lag compressed video.