Is it safe to run multiple COPY commands with NOLOAD attribute?

Question

I want to run muliple COPY commands against single table with NOLOAD attribute.
According to AWS Documentation:

NOLOAD

Checks the validity of the data file without actually loading the data. 

Use the NOLOAD option to make sure that your data file will load without any errors before running the actual data load. Running COPY with the NOLOAD option is much faster than loading the data since it only parses the files.

I know that it's strongly recomended to run a single COPY command against a table. But how about NOLOAD parameter? Is it safe to do?

Answer 1

The recommendation to use just one COPY command at a time is performance related. Since the data is only parsed and not actually serialized for insert this concern is not relevant. You could run multiple COPY commands at once without performance penalty using the NOLOAD flag. You can also use NOLOAD with a manifest.