ASM的優點總結--關於日誌檔案調整

日誌檔案是我們經常關注的,比如出現checkpoint not complete,或者是我們發現alert.log裡日誌切換特頻繁,這個時候就要調整日誌,比如事務總是等待LGWR寫日誌檔案,日誌檔案切換在等歸檔,可能這個時候就要新增日誌組了,利用ASM,可以很容易的規範日誌成員的名字和日誌組的編號.

SQL> l 1* select * from v$logfile SQL> / GROUP# STATUS TYPE MEMBER IS_ ---------- ------- ------- ------------------------------------------------------------ --- 3 ONLINE +DISK_GROUP1/devdb/logfile/redo03.log NO 2 STALE ONLINE +DISK_GROUP1/devdb/logfile/redo02.log NO 1 ONLINE +DISK_GROUP1/devdb/logfile/redo01.log NO 4 STALE ONLINE +DISK_GROUP1/devdb/onlinelog/group_4.273.640618259 NO 4 STALE ONLINE +DISK_GROUP1/devdb/onlinelog/group_4.274.640618265 YES 3 ONLINE +DISK_GROUP1/devdb/logfile/group_3.redo03.log NO 1 ONLINE +DISK_GROUP2/devdb/onlinelog/group_1.277.642080697 NO 已選擇7行。 SQL> select * from v$log; GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------- 1 1 9 52428800 2 YES INACTIVE 254431852 20-1月 -08 2 1 10 52428800 1 YES INACTIVE 254467357 23-1月 -08 3 1 11 52428800 2 NO CURRENT 254506062 23-1月 -08 4 1 8 104857600 2 YES INACTIVE 254407862 19-1月 -08 SQL> SQL> alter database add logfile ('+DISK_GROUP1/devdb/onlinelog/group_5_01.log', 2 '+DISK_GROUP1/devdb/onlinelog/group_5_02.log') size 50m; 資料庫已更改。 --利用手工方式,新增日誌檔案組和成員 SQL> select * from v$log; GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------- 1 1 9 52428800 2 YES INACTIVE 254431852 20-1月 -08 2 1 10 52428800 1 YES INACTIVE 254467357 23-1月 -08 3 1 11 52428800 2 NO CURRENT 254506062 23-1月 -08 4 1 8 104857600 2 YES INACTIVE 254407862 19-1月 -08 5 1 0 52428800 2 YES UNUSED 0 SQL> select * from v$logfile order by group#; GROUP# STATUS TYPE MEMBER IS_ ---------- ------- ------- ------------------------------------------------------------ --- 1 ONLINE +DISK_GROUP1/devdb/logfile/redo01.log NO 1 ONLINE +DISK_GROUP2/devdb/onlinelog/group_1.277.642080697 NO 2 STALE ONLINE +DISK_GROUP1/devdb/logfile/redo02.log NO 3 ONLINE +DISK_GROUP1/devdb/logfile/group_3.redo03.log NO 3 ONLINE +DISK_GROUP1/devdb/logfile/redo03.log NO 4 STALE ONLINE +DISK_GROUP1/devdb/onlinelog/group_4.273.640618259 NO 4 STALE ONLINE +DISK_GROUP1/devdb/onlinelog/group_4.274.640618265 YES 5 ONLINE +DISK_GROUP1/devdb/onlinelog/group_5_01.log NO 5 ONLINE +DISK_GROUP1/devdb/onlinelog/group_5_02.log NO 已選擇9行。 SQL> alter database add logfile group 6 '+DISK_GROUP1' size 50m; 資料庫已更改。 --利用ASM的方式新增日誌組和成員 SQL> select * from v$log; GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------- 1 1 9 52428800 2 YES INACTIVE 254431852 20-1月 -08 2 1 10 52428800 1 YES INACTIVE 254467357 23-1月 -08 3 1 11 52428800 2 NO CURRENT 254506062 23-1月 -08 4 1 8 104857600 2 YES INACTIVE 254407862 19-1月 -08 5 1 0 52428800 2 YES UNUSED 0 6 1 0 52428800 1 YES UNUSED 0 已選擇6行。 SQL> select * from v$logfile order by group#; GROUP# STATUS TYPE MEMBER IS_ ---------- ------- ------- ------------------------------------------------------------ --- 1 ONLINE +DISK_GROUP1/devdb/logfile/redo01.log NO 1 ONLINE +DISK_GROUP2/devdb/onlinelog/group_1.277.642080697 NO 2 STALE ONLINE +DISK_GROUP1/devdb/logfile/redo02.log NO 3 ONLINE +DISK_GROUP1/devdb/logfile/group_3.redo03.log NO 3 ONLINE +DISK_GROUP1/devdb/logfile/redo03.log NO 4 STALE ONLINE +DISK_GROUP1/devdb/onlinelog/group_4.273.640618259 NO 4 STALE ONLINE +DISK_GROUP1/devdb/onlinelog/group_4.274.640618265 YES 5 ONLINE +DISK_GROUP1/devdb/onlinelog/group_5_01.log NO 5 ONLINE +DISK_GROUP1/devdb/onlinelog/group_5_02.log NO 6 ONLINE +DISK_GROUP1/devdb/onlinelog/group_6.261.644775363 NO 已選擇10行。 --我們發現日誌組成員新增是一個成員,ASM是否可以新增兩個呢? SQL> alter database add logfile group 7 ('+DISK_GROUP1','+DISK_GROUP1') size 50m; 資料庫已更改。 SQL> select * from v$logfile order by group#; GROUP# STATUS TYPE MEMBER IS_ ---------- ------- ------- ------------------------------------------------------------ --- 1 ONLINE +DISK_GROUP2/devdb/onlinelog/group_1.277.642080697 NO 1 ONLINE +DISK_GROUP1/devdb/logfile/redo01.log NO 2 STALE ONLINE +DISK_GROUP1/devdb/logfile/redo02.log NO 3 ONLINE +DISK_GROUP1/devdb/logfile/redo03.log NO 3 ONLINE +DISK_GROUP1/devdb/logfile/group_3.redo03.log NO 4 STALE ONLINE +DISK_GROUP1/devdb/onlinelog/group_4.273.640618259 NO 4 STALE ONLINE +DISK_GROUP1/devdb/onlinelog/group_4.274.640618265 YES 5 ONLINE +DISK_GROUP1/devdb/onlinelog/group_5_01.log NO 5 ONLINE +DISK_GROUP1/devdb/onlinelog/group_5_02.log NO 6 ONLINE +DISK_GROUP1/devdb/onlinelog/group_6.261.644775363 NO 7 ONLINE +DISK_GROUP1/devdb/onlinelog/group_7.259.644775421 NO GROUP# STATUS TYPE MEMBER IS_ ---------- ------- ------- ------------------------------------------------------------ --- 7 ONLINE +DISK_GROUP1/devdb/onlinelog/group_7.268.644775419 NO 已選擇12行。

可以看到ASM可以自動新增兩個組成員

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