Help with I/O statistics

I can't make configuration to get "filesystem blocks in/out"
to show valid data.

Im only getting "0/0" all the time.
Is that functionality available in postgres 7.3.1 ???

Regards, Bogdan

------------------------

test4=# explain analyze select * from patients;
LOG: query: explain analyze select * from patients;
LOG: duration: 0.603887 sec
LOG: QUERY STATISTICS
! system usage stats:
! 0.624269 elapsed 0.458985 user 0.123047 system sec
! [0.468750 user 0.125000 sys total]
! 0/0 [0/0] filesystem blocks in/out
! 7/4 [310/158] page faults/reclaims, 0 [0] swaps
! 0 [0] signals rcvd, 0/0 [0/0] messages rcvd/sent
! 0/0 [0/0] voluntary/involuntary context switches
! buffer usage stats:
! Shared blocks: 2742 read, 0 written, buffer hit
rate = 3.59%
! Local blocks: 0 read, 0 written, buffer hit
rate = 0.00%
! Direct blocks: 0 read, 0 written
QUERY PLAN
-----------------------------------------------------------------
Seq Scan on patients (cost=0.00..4048.60 rows=131960 width=172)
(actual time=0.04..562.97 rows=133886 loops=1)
Total runtime: 602.42 msec
(2 rows)

test4=#
test4=# show all;

australian_timezones | off
authentication_timeout | 60
autocommit | on
checkpoint_segments | 3
checkpoint_timeout | 300
client_encoding | SQL_ASCII
client_min_messages | notice
commit_delay | 0
commit_siblings | 5
cpu_index_tuple_cost | 0.001
cpu_operator_cost | 0.0025
cpu_tuple_cost | 0.01
DateStyle | ISO with US (NonEuropean)
conventions
db_user_namespace | off
deadlock_timeout | 1000
debug_assertions | on
debug_pretty_print | on
debug_print_parse | off
debug_print_plan | off
debug_print_rewritten | off
default_statistics_target | 10
default_transaction_isolation | read committed
dynamic_library_path | $libdir
effective_cache_size | 1000
enable_hashjoin | on
enable_indexscan | on
enable_mergejoin | on
enable_nestloop | on
enable_seqscan | on
enable_sort | on
enable_tidscan | on
explain_pretty_print | on
fixbtree | on
fsync | off
geqo | on
geqo_effort | 1
geqo_generations | 0
geqo_pool_size | 0
geqo_random_seed | -1
geqo_selection_bias | 2
geqo_threshold | 11
hostname_lookup | off
krb_server_keyfile | unset
lc_messages | C
lc_monetary | C
lc_numeric | C
lc_time | C
log_connections | off
log_duration | on
log_min_error_statement | panic
log_pid | off
log_statement | on
log_timestamp | off
max_connections | 32
max_expr_depth | 10000
max_files_per_process | 1000
max_fsm_pages | 10000
max_fsm_relations | 100
max_locks_per_transaction | 64
password_encryption | on
port | 5432
pre_auth_delay | 0
random_page_cost | 4
search_path | $user,public
server_encoding | SQL_ASCII
server_min_messages | notice
shared_buffers | 64
show_executor_stats | off
show_parser_stats | off
show_planner_stats | off
show_source_port | off
show_statement_stats | on
silent_mode | off
sort_mem | 1024
sql_inheritance | on
ssl | off
statement_timeout | 0
stats_block_level | off
stats_command_string | off
stats_reset_on_server_start | on
stats_row_level | off
stats_start_collector | on
superuser_reserved_connections | 2
syslog | 0
syslog_facility | LOCAL0
syslog_ident | postgres
tcpip_socket | on
TimeZone | unknown
trace_notify | off
TRANSACTION ISOLATION LEVEL | READ COMMITTED
transform_null_equals | off
unix_socket_directory | unset
unix_socket_group | unset
unix_socket_permissions | 511
vacuum_mem | 8192
virtual_host | unset
wal_buffers | 8
wal_debug | 8
wal_sync_method | fsync
(99 rows)

---------------------------------------------------

Regards, Bogdan