Heikki Linnakangas <hlinn...@iki.fi> writes: > I just noticed that if you load a file using psql: > it sends every line as a separate FE/BE protocol CopyData packet. > ... > I'll add this to the next commitfest. There's similar inefficiency in > the server side in COPY TO, but I'll leave that for another patch.
The FE/BE protocol documentation is pretty explicit about this: Copy-in mode (data transfer to the server) is initiated when the backend executes a COPY FROM STDIN SQL statement. The backend sends a CopyInResponse message to the frontend. The frontend should then send zero or more CopyData messages, forming a stream of input data. (The message boundaries are not required to have anything to do with row boundaries, although that is often a reasonable choice.) ... Copy-out mode (data transfer from the server) is initiated when the backend executes a COPY TO STDOUT SQL statement. The backend sends a CopyOutResponse message to the frontend, followed by zero or more CopyData messages (always one per row), followed by CopyDone. So while changing psql isn't so much a problem, changing the server is a wire protocol break. Maybe we should do it anyway, but I'm not sure. regards, tom lane