Re: pgsql-function

On Tue, Apr 14, 2015 at 10:20 AM, Rishi Ranjan <rishiranjan706@gmail.com> wrote:

we are using version 9.4.

2) The result of above calculation i need to use in different calculation . means output of this calculation will let us to determine the value of  some parameters of other equation like below

y= ((y2-y1)/(x2-x1 ))x+ (y1- (y2-y1)/(x2-x1 ) x1 )

where x1,y1,x2,y2 parameters are defined and whose value need to be picked based on value of x (being calculated from above scenario provided with sample data)

​So, is the real data likely to be as perfect as your sample data or do you need something more robust?​  With the clean data using the lag window function will readily solve your problem.  But if you could guarantee this clean of data I would probably have simply created two columns (and yes, I do know what normalization is) for timestamps - one of which can be null: the "second" one) and perform the query directly.

​David J.​