On Thu, Dec 19, 2019 at 9:46 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > Bruce Momjian <br...@momjian.us> writes: > > How is the attached patch? > > ! In <command>COPY FROM</command>, the number of columns specified > ! must match the number of fields in the file; any table columns not > ! specified in the <command>COPY FROM</command> column list will insert > ! their default values. > > Phrasing seems a bit weird to me: you've run two nearly independent > observations into one sentence. But s/; any/. Any/ might be enough > to fix it. >
Seems better to simply talk about each form independently: If a list of columns is specified, <command>COPY TO</command> will only copy the data in the specified columns to the file. <command>COPY FROM</command> will, by position (i.e., the number of columns listed must match the number of columns in the file), match each file column to the named column in the table. Any additional columns present in the table will receive their default value. David J.