Hello All, I am very new to MonetDB and I am very pleased with its performance at our university. Basically, I have data which is stored on our Unix filesystem. /research_data/life/YYYY/MM/DD/species (there are over 100 species files) I then created a very large csv file which is traverses thru this data. The file size is about 2GB. The table I created looks like this t1 ( t as timestamp species as varchar(10) weight as float color as varchar(10) ) The file species.csv looks like this weigh, color 3,red 7,green 4,blue I have a script that basically traverses thru the filesystem and creates a big csv file for example: 2008-04-01, cat,3,red 2008-04-01, cat,7,green 2008-04-01, cat,4,blue This works fine, but if I run the copy() operation again it will put redundant data. Is there anyway to avoid this?