High consumns memory

I have a software developed in Delphi as a Windows Service, but, i don't
know why, it consumns an unexpected large system memory (1.3g).

The service access PostgresSQL by ODBC driver (psqlodbc_08_03_0400) and it
consist simply of a loop calling a procedure PL/PGSQL. How to discover what
is causing or why this high memory usage ? What objects are being used on
this session ?

Software developed in Delphi 7 as a windows service.

PostgresSQL 8.3.6 Database with PostGis extension

Server p52a

S.O.: Red Hat Enterprise Linux AS release 4 (Nahant Update 1)

linux 2.6.9-11.EL #1 SMP ppc64 ppc64 ppc64 GNU/Linux

S.O. information

top - 11:39:15 up 6 days, 19:15, 1 user, load average: 2.15, 2.02, 1.86

Tasks: 127 total, 1 running, 126 sleeping, 0 stopped, 0 zombie

Cpu(s): 9.5% us, 2.6% sy, 0.0% ni, 71.2% id, 16.3% wa, 0.1% hi, 0.2% si

Mem: 4107392k total, 4101520k used, 5872k free, 17708k buffers

Swap: 2031608k total, 244k used, 2031364k free, 3091708k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND

32662 postgres 16 0 1317m 1.3g 516m D 52.5 32.1 349:57.48 postgres

8953 postgres 17 0 548m 482m 479m S 33.5 12.0 2:50.09 postgres

1944 postgres 16 0 550m 520m 516m S 7.3 13.0 165:30.47 postgres

32659 postgres 15 0 544m 516m 514m S 1.3 12.9 16:42.60 postgres

1935 postgres 15 0 543m 514m 513m S 1.0 12.8 15:15.56 postgres

postgresql.conf information:

name | setting |
unit

---------------------------------+--------------------------------------+------

archive_command | wal_archive_command.sh %p %f |

archive_mode | on |

autovacuum_analyze_scale_factor | 0.4 |

autovacuum_analyze_threshold | 500 |

autovacuum_vacuum_threshold | 1000 |

checkpoint_segments | 15 |

checkpoint_timeout | 1800 | s

DateStyle | ISO, DMY |

default_statistics_target | 50 |

effective_cache_size | 249600 |
8kB

fsync | on |

lc_monetary | en_US.UTF-8 |

lc_numeric | en_US.UTF-8 |

lc_time | en_US.UTF-8 |

listen_addresses | * |

log_autovacuum_min_duration | 0 | ms

log_checkpoints | on |

log_destination | stderr |

log_directory | /p01/log |

log_filename | postgresql-%Y-%m-%d_%H%M%S.log |

log_line_prefix | %t [%p]: [%l-1] |

log_lock_waits | on |

log_min_duration_statement | 250 | ms

log_min_error_statement | error |

log_rotation_age | 1440 |
min

log_rotation_size | 20480 | kB

log_temp_files | 10240 | kB

logging_collector | on |

maintenance_work_mem | 409600 | kB

max_connections | 100 |

max_fsm_pages | 3458000 |

shared_buffers | 64000 |
8kB

tcp_keepalives_idle | 0 | s

wal_buffers | 100 |
8kB

work_mem | 5120 | kB