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