-------------------------------------------------------------------------
| Profiling.								|
-------------------------------------------------------------------------

If PG'OCaml programs are started with the environment variable
$PGPROFILING pointing to the name of a writable file, then profiling
information about events is written to this file.

This information can be analysed later by using the pgocaml_prof tool.

For example:
  PGPROFILING=$HOME/.test_prof
  export PGPROFILING
  ./test
  pgocaml_prof $HOME/.test_prof | less

Information currently tracked includes the running time for SQL
statements and connection time.  You can usually use this information
to find out which statements are taking too long, and optimise them
accordingly.

The profile file will contain some potentially sensitive information
such as database and user names (but not passwords).

