Q:

sql query in shell script @xyz.sql

Can anyone please tell me the exact meaning/significance of @forecast2.sql in below query , the given query is a part of one shell script. Also how can I find the exact sql query executed by @forecast2.sql
Below is the code:
sqlplus -s / @forecast2.sql $SCHED_ID > /tmp/BR_forecast

I need to find the sql query that's been executed here.

A:

This means that sqlplus will execute script called forecast2.sql. 
You could locate it:
> env | grep SQLPATH
-- path where scripts are located

