postgres=#select name,setting,unit,context from pg_settings where name like 'log_%';
name | setting | unit | context
-----------------------------+-----------------------------------------------+------+-------------------
log_autovacuum_min_duration | 60000 | ms | sighup
log_checkpoints | on | | sighup
log_connections | off | | superuser-backend
log_destination | csvlog | | sighup
log_directory | /data/pg_log | | sighup
log_disconnections | off | | superuser-backend
log_duration | off | | superuser
log_error_verbosity | default | | superuser
log_executor_stats | off | | superuser
log_file_mode | 0600 | | sighup
log_filename | postgresql_log.%a | | sighup
log_hostname | off | | sighup
log_line_prefix | %t [%p] [%l-1] user=%u db=%d app=%a client=%h | | sighup
log_lock_waits | on | | superuser
log_min_duration_statement | 60000 | ms | superuser
log_min_error_statement | error | | superuser
log_min_messages | warning | | superuser
log_parser_stats | off | | superuser
log_planner_stats | off | | superuser
log_replication_commands | off | | superuser
log_rotation_age | 1440 | min | sighup
log_rotation_size | 10240 | kB | sighup
log_statement | none | | superuser
log_statement_stats | off | | superuser
log_temp_files | 0 | kB | superuser
log_timezone | Asia/Jakarta | | sighup
log_truncate_on_rotation | on | | sighup
logging_collector | on | | postmaster
name | setting | unit | context
-------------------+---------+------+------------
logging_collector | on | | postmaster
name | setting | unit | context
---------------+--------------+------+---------
log_directory | /data/pg_log | | sighup
name | setting | unit | context
--------------+--------------------------------+------+---------
log_filename | postgresql-%Y-%m-%d_%H%M%S.log | | sighup
可選模式:
1.syslog
2.csvlog
3.sterr
name | setting | unit | context
-----------------+---------+------+---------
log_destination | csvlog | | sighup
name | setting | unit | context
-----------------+-----------------------------------------------+------+---------
log_line_prefix | %t [%p] [%l-1] user=%u db=%d app=%a client=%h | | sighup
參數說明(此部分在postgresql.conf文件中有詳細說明),抄錄如下:
log_line_prefix = ‘%t [%p] [%l-1] user=%u db=%d app=%a client=%h’
# special values:
# %a = application name
# %u = user name
# %d = database name
# %r = remote host and port
# %h = remote host
# %p = process ID
# %t = timestamp without milliseconds
# %m = timestamp with milliseconds
# %n = timestamp with milliseconds (as a Unix epoch)
# %i = command tag
# %e = SQL state
# %c = session ID
# %l = session line number
# %s = session start timestamp
# %v = virtual transaction ID
# %x = transaction ID (0 if none)
# %q = stop here in non-session processes
# %% = ‘%’
# e.g. '<%u%%%d> ’
name | setting | unit | context
--------------------------+---------+------+---------
log_rotation_age | 1440 | min | sighup
log_rotation_size | 10240 | kB | sighup
log_truncate_on_rotation | off | | sighup
以上設置,基本策略將是假如log time>=1440分鐘 or log size>=10240kb,當logfile.log_truncate_on_rotation = off 將會按照
步驟4與步驟5中log_filename雨log_destination中設定的format產生新的logfile,不會覆蓋舊的日誌,隨著時間推移,將會有撐滿disk空間的風險,因此需要定時手工或設定排程刪除舊的日誌文件
輸出範本如下:
postgres@PCNIY-PROD01:/data/pg_log$ ls -alh|sort -k 9
-rw------- 1 postgres postgres 11M Jul 31 23:22 postgresql-2023-07-31_204013.csv
-rw------- 1 postgres postgres 11M Aug 1 02:03 postgresql-2023-07-31_232213.csv
-rw------- 1 postgres postgres 11M Aug 1 04:35 postgresql-2023-08-01_020327.csv
-rw------- 1 postgres postgres 11M Aug 1 07:08 postgresql-2023-08-01_043532.csv
-rw------- 1 postgres postgres 10M Aug 1 08:54 postgresql-2023-08-01_070832.csv
-rw------- 1 postgres postgres 11M Aug 1 10:25 postgresql-2023-08-01_085407.csv
-rw------- 1 postgres postgres 2.4M Aug 1 10:47 postgresql-2023-08-01_102541.csv
如果logfile.log_truncate_on_rotation = on,則會覆蓋原來的日誌。
同時也需要注意該參數只是針對時間到期的切換,如果是因為大小或者系統重啟發生切換時,並不會覆蓋已有的檔。
log_truncate_on_rotation = on # If on, an existing log file with 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.
設置為ON後,結合log_filename設置,可以實現以周為單位的輪轉
name | setting | unit | context
--------------+-------------------+------+---------
log_filename | postgresql_log.%a | | sighup
輸出將是如下:
postgres@pgd-prod01:/data/pg_log$ ls -alh|grep csv
-rw------- 1 postgres postgres 18M Jul 28 23:59 postgresql_log.Fri.csv
-rw------- 1 postgres postgres 12M Jul 31 23:58 postgresql_log.Mon.csv
-rw------- 1 postgres postgres 366K Jul 29 23:57 postgresql_log.Sat.csv
-rw------- 1 postgres postgres 319K Jul 30 23:57 postgresql_log.Sun.csv
-rw------- 1 postgres postgres 19M Jul 27 23:56 postgresql_log.Thu.csv
-rw------- 1 postgres postgres 10M Aug 1 10:56 postgresql_log.Tue.csv
-rw------- 1 postgres postgres 15M Jul 26 23:56 postgresql_log.Wed.csv
可選的選項:none, ddl, mod, all
name | setting | unit | context
---------------------+---------+------+-----------
log_statement | ddl | | superuser
此選項需要注意時間設置,單為為millisecond,設定值太小將會產生過多的log,設置太大又有漏掉低效率的sql的可能
name | setting | unit | context
----------------------------+---------+------+-----------
log_min_duration_statement | 60000 | ms | superuser
以上步驟產生輸出範本如下:
2023-08-01 11:29:26.505 WIB,"wmspci_app","pccwms502Zdb",73203,"172.19.2.74:35852",
64c88352.11df3,1,"SELECT",2023-08-01 11:00:18 WIB,54/7075354,845858776,LOG,00000,
"duration: 1746278.542 ms execute :
select * from pro_sap_to_bom_part($1,$2,$3) as result" ,
"parameters: $1 = '30', $2 = '', $3 = ''",,,,,,,,""