What is a good way to track the timings of queries in postgresql without looking in the log file? -

i've got function in postgres database lot of analysis; consists of succession of update , insert statements , throws output. i'd figure out statements execute slowly, without looking through log files. (i'm more comfortable sql with, say, perl, write date / time arithmetic queries in order spot problems.)

i have table, activity_log:

create table activity_log ( action character varying(250), action_date date, action_tune time without time zone ); 

then throughout function, after each insert / update write statements like

insert activity_log (action_date, action_tune, action)  values (current_date, current_timestamp, 'insert base_model'); 

so function looks this:

create function rebucket(pos_control character varying, absolute_max_cpc numeric, absolute_max_bucket character varying) returns integer $body$ declare qty int;  begin  insert activity_log (action_date, action_tune, action)  values (current_date, current_timestamp, 'off go');  -- takes 5 minutes  insert activity_log (action_date, action_tune, action)  values (current_date, current_timestamp, 'insert base_model');  -- else takes 5 minutes ...  insert activity_log (action_date, action_tune, action)  values (current_date, current_timestamp, 'insert diagnostics');  end  $body$ language plpgsql volatile 

i've got away in other databases in past, when try approach in postgres (9.1 on windows 7), whenever run whole function date , time in activity_log same every statement within function: in example above,

select * activity_log 

gets me

off go              2013-05-13  12:33:23:386 insert base_model   2013-05-13  12:33:23:386 insert diagnostics  2013-05-13  12:33:23:386 

(the function takes 5 minutes hour run, depending on parameters feed it, , has upwards of 20 different statements within there, seems highly unlikely every statement completed within same 1/100th of second.)

why that?

the timestamp using gives start of current transaction. if in manuals see want clock_timestamp().