Support for FOR UPDATE NO WAIT on postgres.

[ybbkrishna]

We are planning to use FOR UPDATE NO WAIT to return with an exception instead of getting blocked on another transaction.

is there any reason this was not added for postgres here ?

If no particular reason, we can raise a PR to support this.

[leazardy]

Hey @Tapac! How I can use it with update statement?
e.g. MyTable.update( {<where statement>}, forUpdate = MODE.SKIP_LOCKED ) { <update statement> }