Re: Running concurrent txns and measuring the timings in Postgres

On 25/7/19 5:24 AM, Souvik Bhattacherjee wrote:
> I got this thing running and hopefully works as expected. The txns are
> stored in insert_txn1.sql, insert_txn2.sql, ...
> Please let me know if you find any issues with this.
> Script is attached.
>
Even if you're using the ancient Bash version 3 (AFAIK only macOS still
uses it out of the box), about half the lines are unnecessary:

#!/bin/bash

SECONDS=0

for i in {1..4}
do
    psql -d mydb -f insert_txn${i}.sql &
done

wait

echo "Elapsed time: $SECONDS secs"

Read the bash man page to understand that SECONDS "magic", and why I
didn't bother with PIDs at all. I also fixed a variable-dereferencing
bug in your original script ("insert_txn[$i].sql" literally expands to
"insert_txn[1].sql", etc.)

Best Regards,
Adrian