Getting current timestamp with nanosecond precision

[SteelBlueVision]

Hi Floris, this codebase should really get extended with the ability to do something similar to:

SELECT CURRENT_TIMESTAMP;

..., (i.e., get the time now with nanosecond precision, which I realize is OS specific). If you would like, I can implement this for Windows/Linux and submit a pull-request, but I may have questions for you along the way.

[fvannee]

I'd be happy to review a PR for a function like that. The pg function is now() so perhaps a function like nsnow()? Happy to accept a better name though.

[higuoxing]

Hi, I've created a PR (#7) to support this feature. But I didn't implement it for Windows platform, it would be good to get some comments from both of you :)