[20221014]資料檔案2的小疑問.txt

[20221014]資料檔案2的小疑問.txt

--//檢視v$dbfile 檢視,發現一點點奇怪的地方,一般資料檔案2都是對應sysaux表空間資料檔案.
--//不知道從怎麼版本開始,oracle的資料檔案2不是sysaux表空間資料檔案.感覺出現PDB開始.

1.環境:
SYS@192.168.100.235:1521/orcl> @ prxx
==============================
PORT_STRING                   : x86_64/Linux 2.4.xx
VERSION                       : 19.0.0.0.0
BANNER                        : Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
BANNER_FULL                   : Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0
BANNER_LEGACY                 : Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
CON_ID                        : 0
PL/SQL procedure successfully completed.

SYS@192.168.100.235:1521/orcl> column name format a70
SYS@192.168.100.235:1521/orcl> select * from v$dbfile order by 1;
     FILE# NAME                                                                       CON_ID
---------- ---------------------------------------------------------------------- ----------
         1 /u02/app/oracle/oradata/orcl/datafile/ORCL/system01.dbf                         0
         2 /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_max_data.dbf                     0
         3 /u02/app/oracle/oradata/orcl/datafile/ORCL/sysaux01.dbf                         0
         4 /u02/app/oracle/oradata/orcl/datafile/ORCL/undotbs01.dbf                        0
         5 /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_data.dbf                         0
         7 /u02/app/oracle/oradata/orcl/datafile/ORCL/users01.dbf                          0
         8 /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_max_data01.dbf                   0
         9 /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_data02.dbf                       0
        10 /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_max_data02.dbf                   0
        11 /u02/app/oracle/oradata/orcl/datafile/ORCL/lis_max_data03.dbf                   0
10 rows selected.
--//一般以前建立資料庫資料檔案2都是屬於sysaux表空間,而這裡建立的資料檔案對應應用軟體的資料檔案.

# ls -li sys* lis_max_data.dbf
52690971 -rw-r-----. 1 oracle oinstall 34359730176 Oct 14 08:37 lis_max_data.dbf
52690958 -rw-r-----. 1 oracle oinstall  3292536832 Oct 14 08:36 sysaux01.dbf
52690957 -rw-r-----. 1 oracle oinstall  1048584192 Oct 14 08:33 system01.dbf
--//從I節點建立的順序看system01.dbf,sysaux01.dbf,lis_max_data.dbf.

--//檢視另外資料庫也是一樣的情況:
SYS@192.168.100.141:1521/dyhis> column name format a70
SYS@192.168.100.141:1521/dyhis> select * from v$dbfile order by 1;
     FILE# NAME                                                                       CON_ID
---------- ---------------------------------------------------------------------- ----------
         1 +DATA/DYHIS/DATAFILE/system.279.1065727197                                      0
         2 +DATA/DYHIS/DATAFILE/users.283.1065727203                                       0
         3 +DATA/DYHIS/DATAFILE/sysaux.269.1065727197                                      0
         4 +DATA/DYHIS/DATAFILE/undotbs1.282.1065727201                                    0
         5 +DATA/DYHIS/DATAFILE/undotbs2.263.1065727197                                    0
...
15 rows selected.

2.為什麼呢?
--//oracle為什麼出現這樣的情況或者設計呢?難道可以使應用軟體的資料檔案近可能在磁碟內圈嗎?那位給出合理的解析.