LogFile Management

After countless tries for configuring postgres logmanagement without success, i hope the community can help me solving the following problem:

I would like to have postgres write logfiles, which must not exceed a specific size all together. After the files have reached the desired size, it would be nice that the files will

a) be overwritten or

b) rotate and are overwritten after reaching the limit of file numbers.

I am sorry to say that log_filename = 'g_pgsql.log%a' is not an option because the logfiles can increase rapidly within a few minutes.

This is the current configuration:

#---------------------------------------------------------------------------

# ERROR REPORTING AND LOGGING

#---------------------------------------------------------------------------

# - Where to Log -

#log_destination = 'stderr' # Valid values are combinations of

# stderr, syslog and eventlog,

# depending on platform.

# This is used when logging to stderr:

redirect_stderr = on # Enable capturing of stderr into log

# files

# (change requires restart)

# These are only used if redirect_stderr is on:

log_directory = '/Library/Application\ Support/Test/PostgreSQL_logs/' # Directory where log files are written

# Can be absolute or relative to PGDATA

log_filename = 'g_pgsql.log' # Log file name pattern.

# Can include strftime() escapes

log_truncate_on_rotation = on # If on, any existing log file of the same

# name as the new log file will be

# truncated rather than appended to. But

# such truncation only occurs on

# time-driven rotation, not on restarts

# or size-driven rotation. Default is

# off, meaning append to existing files

# in all cases.

#log_rotation_age = 0 # Automatic rotation of logfiles will

# happen after that time.  0 to

# disable.

log_rotation_size = 1MB # Automatic rotation of logfiles will

# happen after that much log

# output.  0 to disable.

# These are relevant when logging to syslog:

#syslog_facility = 'LOCAL0'

#syslog_ident = 'postgres'

The generated logfile-names: