postgresql 如何檢視pg_wal目錄下xlog檔案總大小
阿新 • • 發佈:2021-01-15
當然如果你登入伺服器所在主機,直接在$PGDAT/pg_wal下執行:
du -h --max-depth=1 ./
可以得到。
#du -h --max-depth=1 ./ 4.0K ./archive_status 193M ./
如果通過客戶端怎麼做呢?
答案:pg_ls_waldir()函式。pg_ls_waldir()是pg 10.0引入的函式,可以輸出資料庫WAL目錄的所有檔案。
postgres=# select sum(size) from pg_ls_waldir(); sum ----------- 201326592 (1 row)
單位是byte,所以當前pg_wal的xlog日誌總大小為201326592/1024/1024=192M。
也可以使用:
postgres=# select count(*) from pg_ls_waldir(); count ------- 12 (1 row)
12表示wal日誌檔案個數,總大小12*16=192M。
16表示單個wal日誌檔案大小,單位MB,WAL 日誌檔案大小預設為16MB。
bonus:
1、怎麼調整單個wal日誌檔案大小?
答:使用 initdb 調整WAL檔案大小。
2、pg_ls_logdir() 也是pg10.0版本引入的函式,輸出資料庫日誌目錄的所有檔案。
postgres=# select * from pg_ls_logdir(); name | size | modification ----------------------------------+---------+------------------------ postgresql-2020-04-28_092020.log | 2277343 | 2020-04-29 11:34:56+08 postgresql-2020-04-28_092020.csv | 140050 | 2020-04-29 11:34:56+08
3、如何列出/data資料夾中的檔案?
答:pg_ls_dir
postgres=# select pg_ls_dir('/data'); pg_ls_dir ----------------------
補充:postgresql 檢視wal生成頻率和大小
–wal 檔案生成數量
–linux ls --full-time stat filename
–pg_stat_file返回一個記錄,其中包含
– 1 size 檔案尺寸
– 2 access 最後訪問時間戳(linux:最近訪問) 、
– 3 modification 最後修改時間戳(linux:最近更改–) 、
– 4 change 最後檔案狀態改變時間戳(只支援 Unix 平臺)(linux:最近改動) 、
– 5 creation 檔案建立時間戳(只支援 Windows)
– 6 isdir 一個boolean指示它是否為目錄 isdir
– select * from pg_stat_file('/var/lib/postgresql/9.1/main/pg_xlog/0000000200000BBB000000A9'); – /var/lib/postgresql/9.1/main/pg_xlog – /var/log/postgresql – /mnt/nas_dbbackup/archivelog
with tmp_file as ( select t1.file,t1.file_ls,(pg_stat_file(t1.file)).size as size,(pg_stat_file(t1.file)).access as access,(pg_stat_file(t1.file)).modification as last_update_time,(pg_stat_file(t1.file)).change as change,(pg_stat_file(t1.file)).creation as creation,(pg_stat_file(t1.file)).isdir as isdir from (select dir||'/'||pg_ls_dir(t0.dir) as file,pg_ls_dir(t0.dir) as file_ls from ( select '/var/lib/postgresql/9.1/main/pg_xlog'::text as dir --需要修改這個物理路徑 --select '/mnt/nas_dbbackup/archivelog'::text as dir --select setting as dir from pg_settings where name='log_directory' ) t0 ) t1 where 1=1 order by (pg_stat_file(file)).modification desc ) select to_char(date_trunc('day',tf0.last_update_time),'yyyymmdd') as day_id,sum(case when date_part('hour',tf0.last_update_time) >=0 and date_part('hour',tf0.last_update_time) <24 then 1 else 0 end) as wal_num_all,tf0.last_update_time) <1 then 1 else 0 end) as wal_num_00_01,tf0.last_update_time) >=1 and date_part('hour',tf0.last_update_time) <2 then 1 else 0 end) as wal_num_01_02,tf0.last_update_time) >=2 and date_part('hour',tf0.last_update_time) <3 then 1 else 0 end) as wal_num_02_03,tf0.last_update_time) >=3 and date_part('hour',tf0.last_update_time) <4 then 1 else 0 end) as wal_num_03_04,tf0.last_update_time) >=4 and date_part('hour',tf0.last_update_time) <5 then 1 else 0 end) as wal_num_04_05,tf0.last_update_time) >=5 and date_part('hour',tf0.last_update_time) <6 then 1 else 0 end) as wal_num_05_06,tf0.last_update_time) >=6 and date_part('hour',tf0.last_update_time) <7 then 1 else 0 end) as wal_num_06_07,tf0.last_update_time) >=7 and date_part('hour',tf0.last_update_time) <8 then 1 else 0 end) as wal_num_07_08,tf0.last_update_time) >=8 and date_part('hour',tf0.last_update_time) <9 then 1 else 0 end) as wal_num_08_09,tf0.last_update_time) >=9 and date_part('hour',tf0.last_update_time) <10 then 1 else 0 end) as wal_num_09_10,tf0.last_update_time) >=10 and date_part('hour',tf0.last_update_time) <11 then 1 else 0 end) as wal_num_10_11,tf0.last_update_time) >=11 and date_part('hour',tf0.last_update_time) <12 then 1 else 0 end) as wal_num_11_12,tf0.last_update_time) >=12 and date_part('hour',tf0.last_update_time) <13 then 1 else 0 end) as wal_num_12_13,tf0.last_update_time) >=13 and date_part('hour',tf0.last_update_time) <14 then 1 else 0 end) as wal_num_13_14,tf0.last_update_time) >=14 and date_part('hour',tf0.last_update_time) <15 then 1 else 0 end) as wal_num_14_15,tf0.last_update_time) >=15 and date_part('hour',tf0.last_update_time) <16 then 1 else 0 end) as wal_num_15_16,tf0.last_update_time) >=16 and date_part('hour',tf0.last_update_time) <17 then 1 else 0 end) as wal_num_16_17,tf0.last_update_time) >=17 and date_part('hour',tf0.last_update_time) <18 then 1 else 0 end) as wal_num_17_18,tf0.last_update_time) >=18 and date_part('hour',tf0.last_update_time) <19 then 1 else 0 end) as wal_num_18_19,tf0.last_update_time) >=19 and date_part('hour',tf0.last_update_time) <20 then 1 else 0 end) as wal_num_19_20,tf0.last_update_time) >=20 and date_part('hour',tf0.last_update_time) <21 then 1 else 0 end) as wal_num_20_21,tf0.last_update_time) >=21 and date_part('hour',tf0.last_update_time) <22 then 1 else 0 end) as wal_num_21_22,tf0.last_update_time) >=22 and date_part('hour',tf0.last_update_time) <23 then 1 else 0 end) as wal_num_22_23,tf0.last_update_time) >=23 and date_part('hour',tf0.last_update_time) <24 then 1 else 0 end) as wal_num_23_24 from tmp_file tf0 where 1=1 and tf0.file_ls not in ('archive_status') group by to_char(date_trunc('day','yyyymmdd') order by to_char(date_trunc('day','yyyymmdd') desc ;
以上為個人經驗,希望能給大家一個參考,也希望大家多多支援我們。如有錯誤或未考慮完全的地方,望不吝賜教。