The PGDBG command prompt reflects the current debug mode (See PGDBG Debug Modes and Process/Thread Identifiers).
In serial debug mode, the PGDBG prompt looks like this:
pgdbg>
In threads-only debug mode, PGDBG displays the current p/t-set followed by the ID of the current thread.
pgdbg [all] 0> Current thread is 0
In process-only debug mode, PGDBG displays the current p/t-set followed by the ID of the current process.
pgdbg [all] 0> Current process is 0
In multilevel debug mode, PGDBG displays the current p/t-set followed by the ID of the current thread prefixed by the id of its parent process.
pgdbg [all] 1.0> Current thread 1.0
The pgienv promptlen variable can be set to control the number of characters devoted to printing the current p/t-set at the prompt.
See PGDBG Debug Modes and Process/Thread Identifiers for a description of the PGDBG debug modes.