How to solve error in pg_top stating "relation does not exist"

When you execute pg_top, you get to see the top database sessions in a way familiar to most people with experience from Unix environments.

There are many options to pg_top, and one that I wanted to use, was

E       - show execution plan (UPDATE/DELETE safe)

When you press E, you are prompted for a process ID:

Re-determine execution plan: 119692

But I kept getting the message:

Query Plan:

ERROR:  relation "myschema.mytable" does not exist
LINE 4:     from myschema.mytable
                 ^
Hit any key to continue:

Solution: Execute pg_top with database name, host name, port, username and password, like this:

$ pg_top -d mydb -h myhost.mydomain.com -p 5432  -U mysuperuser -W

After I executed pg_top in this manner, the E option worked as exected and displayed the execution plan.