Save MySQL data to compressed CSV file using a FIFO named pipe

It's very easy to save MySQL data to a compressed file by using a named pipe.
You need to have two bash terminals open, A & B, presumably in screen/tmux sessions since you are likely interested in large tables that take a long time to export.

Terminal A, Step 1: Create the FIFO named pipe (make sure MySQL can write to it):

mkfifo "/path/to/data.csv"
sudo chown mysql "/path/to/data.csv"

Terminal A, Step 2: Have zstd read from the FIFO pipe and write to an output file:

zstd -o "/tmp/data.csv.zst" < "/path/to/data.csv" &

Terminal B: Save the MySQL data:

SELECT * FROM your_table

 INTO OUTFILE '/path/to/data.csv'

 CHARACTER SET UTF8MB4

 FIELDS TERMINATED BY ','

        OPTIONALLY ENCLOSED BY '"'

        ESCAPED BY '"'

 LINES TERMINATED BY '\n';

The only issue would be the NULL columns, which  you can deal with manually by using IFNULL when constructing your query.

https://www.w3schools.com/sql/func_mysql_ifnull.asp