Oracle10g ASM I/O Balancing query [message #117405] |
Wed, 27 April 2005 02:05 |
girish.rohini
Messages: 744 Registered: April 2005 Location: Delhi (India)
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Senior Member |
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Hi
I am new to using ASM in Oracle 10g and have a few queries about it:
1. I have 1 disk group consisting of say 3 disks with varying I/O rate. Now since ASM do balances I/O among disks in a disk group, my query is how ASM will manage it in this case.
2. A datafile does get stored on disk. Now, when we use ASM and query the v$datafile view, what path will it show fro the datafile. Will it be the path referencing the disk group or actual path of file, we get to see when execute the same query in earlier versions of Oracle.
Thnx in advance for ur responses.
Regds
Girish
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Re: Oracle10g ASM I/O Balancing query [message #117773 is a reply to message #117405] |
Fri, 29 April 2005 09:56 |
Frank Naude
Messages: 4587 Registered: April 1998
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Senior Member |
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Hi,
Answers:
1) Oracle would not know that some disks are slower than others. It would thus be best to add these disks to separate disk groups.
2) It depends on how your created it - with or without an alias. Here is an example without using an alias.
SQL> create tablespace test datafile '+TESTDG' size 10m;
Tablespace created.
SQL> select file_name from dba_data_files where tablespace_name = 'TEST';
FILE_NAME
--------------------------------------------------------------------------------
+TESTDG/orcl/datafile/test.256.1
Another example - this time we use alias "test1.dbf":
SQL> create tablespace test2 datafile '+TESTDG/mydbfiles/test1.dbf' size 10m;
Tablespace created.
SQL> select file_name from dba_data_files where tablespace_name = 'TEST2';
FILE_NAME
-------------------------------------------------------------------------------
+TESTDG/mydbfiles/test1.dbf
Best regards.
Frank
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