log_min_duration_statement

Hi Team,,

I have set log_min_duration_statement=1000 as my configuration but when i
observe log file i could see queries that ran below 1000ms are also getting
logged , for instance
duration: 0.089 ms
duration: 0.175 ms
duration: 0.139 ms
duration: 0.451 ms
duration: 0.136 ms
duration: 0.340 ms
duration: 0.150 ms
duration: 0.440 ms
duration: 0.338 ms
duration: 0.156 ms
tion: 0.396 ms
duration: 0.221 ms
duration: 0.161 ms
*************
these are my logsettings

name | setting
---------------------------------+---------------------------------------------------
log_autovacuum_min_duration | 0
log_checkpoints | on
log_connections | on
log_destination | syslog
log_directory | log
log_disconnections | on
log_duration | off
log_error_verbosity | default
log_executor_stats | off
log_file_mode | 0600
log_filename | postgresql-%Y-%m-%d_%H%M%S.log
log_hostname | off
log_line_prefix |
appname=%a,user=%u,db=%d,pid=%p,txid=%x,vtxid=%v
log_lock_waits | on
log_min_duration_statement | 1000
log_min_error_statement | error
log_min_messages | error
log_parser_stats | off
log_planner_stats | off
log_replication_commands | off
log_rotation_age | 1440
log_rotation_size | 10240
log_statement | all
log_statement_stats | off
log_temp_files | 0
log_timezone | Navajo
log_truncate_on_rotation | off
logging_collector | on
max_logical_replication_workers | 4
syslog_facility | local4
syslog_ident | postgres
syslog_sequence_numbers | on
syslog_split_messages | on
wal_log_hints | off

Regards,
Bhargav K