postgresql 查看wal生成频率和大小

–wal 文件生成数量
–linux ls --full-time stat filename
–pg_stat_file返回一个记录，其中包含
– 1 size 文件尺寸
– 2 access 最后访问时间戳(linux:最近访问) 、
– 3 modification 最后修改时间戳(linux:最近更改–) 、
– 4 change 最后文件状态改变时间戳（只支持 Unix 平台）(linux:最近改动) 、
– 5 creation 文件创建时间戳（只支持 Windows）
– 6 isdir 一个boolean指示它是否为目录 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
                     --需要修改这个物理路径
                     --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,
        sum(case when date_part('hour',tf0.last_update_time) >=0  and date_part('hour',tf0.last_update_time) <1  then 1 else 0 end) as wal_num_00_01,
        sum(case when date_part('hour',tf0.last_update_time) >=1  and date_part('hour',tf0.last_update_time) <2  then 1 else 0 end) as wal_num_01_02,
        sum(case when date_part('hour',tf0.last_update_time) >=2  and date_part('hour',tf0.last_update_time) <3  then 1 else 0 end) as wal_num_02_03,
        sum(case when date_part('hour',tf0.last_update_time) >=3  and date_part('hour',tf0.last_update_time) <4  then 1 else 0 end) as wal_num_03_04,
        sum(case when date_part('hour',tf0.last_update_time) >=4  and date_part('hour',tf0.last_update_time) <5  then 1 else 0 end) as wal_num_04_05,
        sum(case when date_part('hour',tf0.last_update_time) >=5  and date_part('hour',tf0.last_update_time) <6  then 1 else 0 end) as wal_num_05_06,
        sum(case when date_part('hour',tf0.last_update_time) >=6  and date_part('hour',tf0.last_update_time) <7  then 1 else 0 end) as wal_num_06_07,
        sum(case when date_part('hour',tf0.last_update_time) >=7  and date_part('hour',tf0.last_update_time) <8  then 1 else 0 end) as wal_num_07_08,
        sum(case when date_part('hour',tf0.last_update_time) >=8  and date_part('hour',tf0.last_update_time) <9  then 1 else 0 end) as wal_num_08_09,
        sum(case when date_part('hour',tf0.last_update_time) >=9  and date_part('hour',tf0.last_update_time) <10 then 1 else 0 end) as wal_num_09_10,
        sum(case when date_part('hour',tf0.last_update_time) >=10 and date_part('hour',tf0.last_update_time) <11 then 1 else 0 end) as wal_num_10_11,
        sum(case when date_part('hour',tf0.last_update_time) >=11 and date_part('hour',tf0.last_update_time) <12 then 1 else 0 end) as wal_num_11_12,
        sum(case when date_part('hour',tf0.last_update_time) >=12 and date_part('hour',tf0.last_update_time) <13 then 1 else 0 end) as wal_num_12_13,
        sum(case when date_part('hour',tf0.last_update_time) >=13 and date_part('hour',tf0.last_update_time) <14 then 1 else 0 end) as wal_num_13_14,
        sum(case when date_part('hour',tf0.last_update_time) >=14 and date_part('hour',tf0.last_update_time) <15 then 1 else 0 end) as wal_num_14_15,
        sum(case when date_part('hour',tf0.last_update_time) >=15 and date_part('hour',tf0.last_update_time) <16 then 1 else 0 end) as wal_num_15_16,
        sum(case when date_part('hour',tf0.last_update_time) >=16 and date_part('hour',tf0.last_update_time) <17 then 1 else 0 end) as wal_num_16_17,
        sum(case when date_part('hour',tf0.last_update_time) >=17 and date_part('hour',tf0.last_update_time) <18 then 1 else 0 end) as wal_num_17_18,
        sum(case when date_part('hour',tf0.last_update_time) >=18 and date_part('hour',tf0.last_update_time) <19 then 1 else 0 end) as wal_num_18_19,
        sum(case when date_part('hour',tf0.last_update_time) >=19 and date_part('hour',tf0.last_update_time) <20 then 1 else 0 end) as wal_num_19_20,
        sum(case when date_part('hour',tf0.last_update_time) >=20 and date_part('hour',tf0.last_update_time) <21 then 1 else 0 end) as wal_num_20_21,
        sum(case when date_part('hour',tf0.last_update_time) >=21 and date_part('hour',tf0.last_update_time) <22 then 1 else 0 end) as wal_num_21_22,
        sum(case when date_part('hour',tf0.last_update_time) >=22 and date_part('hour',tf0.last_update_time) <23 then 1 else 0 end) as wal_num_22_23, 
        sum(case when date_part('hour',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',tf0.last_update_time),'yyyymmdd')
order by to_char(date_trunc('day',tf0.last_update_time),'yyyymmdd') desc
;