每天 TB 大小的归档存储

Question

我正在研究 Oracle 数据库。归档存储高达每天 TB 级别。我需要解决这个问题。如何检测引起数据库变化最多的表达式（dml + ddl）？你可以检查这张图片。

Answer 1

有日志挖掘pl/sql，你可以在oracle功能中开启，sql可以看到archivelog的内容，然后你就可以知道，是什么生成了这么多archivelog。

请参阅以下内容link（但您需要担任 dba 角色才能启用和跟踪存档日志的内容）

https://docs.oracle.com/cd/B19306_01/server.102/b14215/logminer.htm

斯科特

Answer 2

虽然我不认为有一种方法可以直接测量每个语句生成的存档日志量 space，但有几个简单的查询可以测量与存档日志密切相关的事物 space.

使用视图 GV$SQL 查找使用时间最多的 non-SELECT SQL 语句。 longest-running DML 和 DDL 语句通常是写入最多数据的语句。根据我的经验，只要查看此查询的结果，SQL 语句之一就会成为罪魁祸首。

select round(elapsed_time/1000000) seconds, gv$sql.*
from gv$sql
where command_type <> 3 --ignore SELECT statements.
order by seconds desc;

使用视图 DBA_HIST_SQLSTAT 查找在过去一天生成最多物理写入的 SQL 语句。这些结果也可能具有误导性，因为 direct-path 写入不会生成 REDO 和归档日志数据。但是罪魁祸首很可能位于此查询结果的顶部。（此视图需要获得诊断包的许可 - 它是 AWR 的一部分。）

select sql_id, round(physical_write_bytes_total/1024/1024) mb, dba_hist_sqlstat.*
from dba_hist_sqlstat
where (snap_id, dbid) in
(
    --Snapshots in the last 24 hours.
    select snap_id, dbid
    from dba_hist_snapshot
    where begin_interval_time >= sysdate - interval '240' hour
)
order by dba_hist_sqlstat.physical_write_bytes_total desc;

Answer 3

这将为您提供全天 log-switches 何时发生的图形视图。 https://www.morganslibrary.org/reference/log_files.html

set echo on
/*
Look for anomalies in log switch frequency and
switch frequencies greater than 12 per hour.
*/

set echo off
select
  to_char(first_time,'MMDD') MMDD,
  to_char(sum(decode(to_char(first_time,'HH24'),'00',1,0)),'999') "00",
  to_char(sum(decode(to_char(first_time,'HH24'),'01',1,0)),'999') "01",
  to_char(sum(decode(to_char(first_time,'HH24'),'02',1,0)),'999') "02",
  to_char(sum(decode(to_char(first_time,'HH24'),'03',1,0)),'999') "03",
  to_char(sum(decode(to_char(first_time,'HH24'),'04',1,0)),'999') "04",
  to_char(sum(decode(to_char(first_time,'HH24'),'05',1,0)),'999') "05",
  to_char(sum(decode(to_char(first_time,'HH24'),'06',1,0)),'999') "06",
  to_char(sum(decode(to_char(first_time,'HH24'),'07',1,0)),'999') "07",
  to_char(sum(decode(to_char(first_time,'HH24'),'08',1,0)),'999') "08",
  to_char(sum(decode(to_char(first_time,'HH24'),'09',1,0)),'999') "09",
  to_char(sum(decode(to_char(first_time,'HH24'),'10',1,0)),'999') "10",
  to_char(sum(decode(to_char(first_time,'HH24'),'11',1,0)),'999') "11",
  to_char(sum(decode(to_char(first_time,'HH24'),'12',1,0)),'999') "12",
  to_char(sum(decode(to_char(first_time,'HH24'),'13',1,0)),'999') "13",
  to_char(sum(decode(to_char(first_time,'HH24'),'14',1,0)),'999') "14",
  to_char(sum(decode(to_char(first_time,'HH24'),'15',1,0)),'999') "15",
  to_char(sum(decode(to_char(first_time,'HH24'),'16',1,0)),'999') "16",
  to_char(sum(decode(to_char(first_time,'HH24'),'17',1,0)),'999') "17",
  to_char(sum(decode(to_char(first_time,'HH24'),'18',1,0)),'999') "18",
  to_char(sum(decode(to_char(first_time,'HH24'),'19',1,0)),'999') "19",
  to_char(sum(decode(to_char(first_time,'HH24'),'20',1,0)),'999') "20",
  to_char(sum(decode(to_char(first_time,'HH24'),'21',1,0)),'999') "21",
  to_char(sum(decode(to_char(first_time,'HH24'),'22',1,0)),'999') "22",
  to_char(sum(decode(to_char(first_time,'HH24'),'23',1,0)),'999') "23"
from
  v$log_history
group by to_char(first_time,'MMDD')
order by 1;

祝你好运！

每天 TB 大小的归档存储

Terabyte size archive storage per day

oracle

ddl

plsql

archive

dml