The following creates a table and insert one row where the first column is filled in using the default value (a sequence) and the other columns come from a file. When doing this, the NULL AS blurb gets ignored.
create table t (id int auto_increment, a clob, b clob);
copy 1 records into t (a, b) from stdin (id, a, b) using delimiters ',','\n','"' null as '';
select * from t;
this now results in a row with values id=1, a='', b='' instead of id=1,a=NULL,b=NULL.
The first column must be in the file, but it must be ignored by the COPY IN.
Changeset e2fda4b58c9f, made by Sjoerd Mullender <firstname.lastname@example.org> in the MonetDB repo, refers to this bug.
For complete details, see https://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=e2fda4b58c9f
Don't skip checking for nullstr when skipping first column.
This fixes bug 6532.
The Mar2018 version has been released.