Yes, fishing in a small tile of water walled off by shore and/or rocks on three of the 4 sides decreases the chance of "Nothing seems to be biting..." message. This does not reduce the chances of not catching anything to 0, but it is considerably better than it is otherwise.

However, if you are chain-fishing for shiny Pokemon, your best bet is is to have your lead Pokemon have the ability Suction Cups or Sticky Hold. If the Pokemon you've chosen for the task is under-leveled compared to what you are fishing, having it hold something like a smoke ball will allow you to flee from the hordes of non-shinies without fail.

For more information on how chain-fishing works (specifically what will and will not break the chain) see this question/answer; How does chain fishing work?

Where are the fishing spots surrounded by rocks etc, and do they actually increase the chances of catching fish?
I had a question surrounding the COPY command in PostgreSQL. I have a CSV file that I only want to copy some of the columns values into my PostgreSQL table.

Is it possible to do this? I am familiar with using the COPY command to copy all of the data from a CSV into a table using the header to map to the column names but how is this possible when I only want some of the columns?
