How to unload a table on RedShift to a single CSV file?

Question

I want to migrate a table from Amazon RedShift to MySQL, but using \"unload\" will generate multiple data files which are hard to imported into MySQL directly.

Is there

Answer 1

There is no way to force Redshift to generate only a single output file, for sure.

Under a standard UNLOAD you will have output files created equivalent to the number of system slices, i.e. a system with 8 slices will create 8 files for a single unload command(This is the fastest method to unload.)

If you add a clause PARALLEL OFF in to he Unload Command, your output will be created as a single file, upto the time where the data extract soze does not go beyond 6.25GB, after which Redshift will automatically break the file into a new chunk.

The same thing holds true, if you produce compressed output files as well(There of course you will have greater chances to produce a single output file, considering that your file can accommodate more number of records in it.).